www.keithley.com Model 6220 DC Current Source Model 6221 AC and DC Current Source User’s Manual 622x-900-01 Rev.
WARRANTY Keithley Instruments, Inc. warrants this product to be free from defects in material and workmanship for a period of 1 year from date of shipment. Keithley Instruments, Inc. warrants the following items for 90 days from the date of shipment: probes, cables, rechargeable batteries, diskettes, and documentation. During the warranty period, we will, at our option, either repair or replace any product that proves to be defective.
Model 6220 DC Current Source Model 6221 AC and DC Current Source User’s Manual ©2004, Keithley Instruments, Inc. All rights reserved. Cleveland, Ohio, U.S.A. Second Printing, June 2005 Document Number: 622x-900-01 Rev.
Manual Print History The print history shown below lists the printing dates of all Revisions and Addenda created for this manual. The Revision Level letter increases alphabetically as the manual undergoes subsequent updates. Addenda, which are released between Revisions, contain important change information that the user should incorporate immediately into the manual. Addenda are numbered sequentially.
Safety Precautions The following safety precautions should be observed before using this product and any associated instrumentation. Although some instruments and accessories would normally be used with non-hazardous voltages, there are situations where hazardous conditions may be present. This product is intended for use by qualified personnel who recognize shock hazards and are familiar with the safety precautions required to avoid possible injury.
bles or jumpers, installing or removing switching cards, or making internal changes, such as installing or removing jumpers. Do not touch any object that could provide a current path to the common side of the circuit under test or power line (earth) ground. Always make measurements with dry hands while standing on a dry, insulated surface capable of withstanding the voltage being measured.
Table of Contents 1 Getting Started Introduction ............................................................................................................. 1-2 User’s Manual content and structure ............................................................... 1-2 Capabilities and features .................................................................................. 1-2 General information ................................................................................................
2 Output Connections Output connectors ................................................................................................... 2-2 Triax connector ................................................................................................ 2-2 Ground points .................................................................................................. 2-3 LO and GUARD banana jacks ........................................................................ 2-3 INTERLOCK .....................
Front panel sweep operation ................................................................................... 4-5 Using the sweep configuration menu ............................................................... 4-5 Performing a staircase sweep ........................................................................... 4-6 Performing a custom sweep ............................................................................. 4-7 Remote sweep operation .....................................................
6 Averaging Filter, Math, and Buffer Averaging filter ....................................................................................................... Averaging filter characteristics ........................................................................ Filter setup and control .................................................................................... Remote programming – Averaging filter ........................................................ Math .....................................
List of Illustrations 1 Getting Started Figure 1-1 Figure 1-2 Figure 1-3 Models 6220 and 6621 front panels .................................................................... 1-5 Model 622x rear panel ........................................................................................ 1-8 Menu editing keys .............................................................................................
7 Wave Functions (6221 Only) Figure 7-1 Figure 7-2 Figure 7-3 Offset example ................................................................................................... 7-4 Duty cycle .......................................................................................................... 7-5 Phase marker ......................................................................................................
List of Tables 3 DC Current Source Operation Table 3-1 Table 3-2 Source ranges and maximum outputs ................................................................. 3-2 DC output commands ....................................................................................... 3-15 4 Sweeps Table 4-1 Table 4-2 Table 4-3 Table 4-4 Sweep configuration menu ................................................................................. 4-5 Sweep example parameters .......................................
1 Getting Started Section 1 topics Introduction, page 1-2 User’s Manual content and structure, page 1-2 Capabilities and features, page 1-2 Menus, page 1-13 CONFIG menus, page 1-13 Direct access menus, page 1-13 General information, page 1-3 Warranty information, page 1-3 Contact information, page 1-3 Safety symbols and terms, page 1-3 Unpacking and inspection, page 1-3 Options and accessories, page 1-4 Editing controls, page 1-14 Source and compliance editing, page 1-14 Menu navigation, page 1-14 Passw
1-2 Getting Started Model 6220/6221 User’s Manual Introduction User’s Manual content and structure This User’s Manual is provided as a hardcopy and is also provided on the supplied Product Information CD in PDF format. The User’s Manual is an abbreviated version of the operation sections of the Reference Manual. The seven sections of the User’s Manual correspond (in abbreviated form) to the first seven sections of the Reference Manual. The Reference Manual is on the Product Information CD in PDF format.
Model 6220/6221 User’s Manual Getting Started 1-3 General information Warranty information Warranty information is located at the front of this manual. Should your Model 622x require warranty service, contact the Keithley representative or authorized repair facility in your area for further information. When returning the instrument for repair, be sure to fill out and include the service form at the back of this manual to provide the repair facility with the necessary information.
1-4 Getting Started Model 6220/6221 User’s Manual to the shipping agent immediately. Save the original packing carton for possible future shipment. Before removing the Model 622x from the bag, observe the following handling precautions. Handling precautions • • • Always grasp the Model 622x by the covers. After removing the Model 622x from its anti-static bag, inspect it for any obvious signs of physical damage. Report any such damage to the shipping agent immediately.
Model 6220/6221 User’s Manual Getting Started 1-5 Figure 1-1 Models 6220 and 6621 front panels Model 6220: 6220 PRECISION CURRENT SOURCE MODE EDIT/ LOCAL CONFIG POWER FILT PRES DC SWP 0 1 2 3 COMM ADDR DISP TRIG 8 9 6 7 SAVE SETUP TRIAX COND 4 RANGE 5 AUTO UNITS RECALL +/- AVG 1 DELTA RANGE 0000 MATH MENU EXIT ENTER 2 OUTPUT ON/OFF 3 4 PU R N TO E DIT / E SH TO E DIT / E TE TE SH N Model 6221: PU R 6221 DC AND AC CURRENT SOURCE MODE EDIT/ LOCAL CONFIG
1-6 Getting Started Model 6220/6221 User’s Manual 1 Special keys and power switch: EDIT/LOCAL Dual function – While in local, EDIT selects the source editing mode. While in remote, LOCAL cancel the remote mode. CONFIG Use to configure a function or operation. POWER Power switch – In position turns 622x on (I), out position turns it off (O). 2 Function and operation keys: Top Row FILT PRES DC SWP COND DELTA Enables/disables analog filter. Enables/disables the pre-set source value.
Model 6220/6221 User’s Manual Getting Started 1-7 Bottom Row SAVE SETUP TRIAX AVG MATH MENU EXIT ENTER Saves up to five instrument setups for future recall, and selects power-on setup. Restores a default setup (preset or *RST) or a user saved setup. Configures triax connector: Inner shield and Output Low. Can also press CONFIG > TRIAX to configure triax connector. Enables/disables averaging filter. Press CONFIG > AVG to configure averaging filter. Enables/disable math.
1-8 Getting Started Model 6220/6221 User’s Manual Rear panel summaries The rear panel of the Models 622x is shown in Figure 1-2. The Model 6221 rear panel is shown, but the Model 6220 is identical except it does not have the Ethernet connector. The descriptions of the rear panel components follow Figure 1-2. Figure 1-2 Model 622x rear panel NOTE The rear panels of the Model 6220 and 6221 are the same, except the Model 6220 does not have an Ethernet connector (3). HI INTERNALLY SWITCHED 1 AMP MAX.
Model 6220/6221 User’s Manual Getting Started 1-9 4 DIGITAL I/O Male DB-9 connector. Four pins for digital output, one pin for Start of Test (SOT) trigger, and one for external voltage (VEXT) input. 5 RS-232 Female DB-9 connector: • For RS-232 operation, use a straight-through (not null modem) DB-9 shielded cable for connection to the PC. • For Delta, Pulse Delta, and Differential Conductance, use the supplied serial cable (CA-351) for connections between the Model 622x and the Model 2182/2182A.
1-10 Getting Started Model 6220/6221 User’s Manual WARNING When handling the Model 622x, NEVER touch the heat sink located on the right side of the case. This heat sink could be hot enough to cause burns. CAUTION NEVER place a container of liquid (e.g., water, coffee, etc.) on the top cover. If it spills, the liquid will enter the case through the vents and cause severe damage. Excessive heat could damage the Model 622x and at the very least, degrade its performance.
Model 6220/6221 User’s Manual Getting Started 1-11 • • Rack mounting high power dissipation equipment adjacent to the Model 622x could cause excessive heating to occur. The specified ambient temperature must be maintained around the surfaces of the Model 622x to specified accuracies. A good measure to ensure proper cooling in rack situations with convection cooling only is to place the hottest equipment (e.g., power supply) at the top of the rack.
1-12 Getting Started Model 6220/6221 User’s Manual WARNING 3. The power cord supplied with the Model 622x contains a separate ground wire for use with grounded outlets. When proper connections are made, instrument chassis is connected to power line ground through the ground wire in the power cord. Failure to use a grounded outlet may result in personal injury or death due to electric shock. Turn on the instrument by pressing the front panel power switch to the on (I) position.
Model 6220/6221 User’s Manual Getting Started 1-13 Menus Many aspects of operation are configured through menus. A direct access menu can be opened by pressing a single key, and other menus require that the CONGIF key be pressed before pressing another key. CONFIG menus NOTE “Press CONFIG > Press SWP” is an example of a keypress sequence. To open the menu, press the CONFIG key and then the SWP key. Models 6220 and 6221: CONFIG > SWP opens CONFIGURE SWEEPS menu (Section 4).
1-14 Getting Started Model 6220/6221 User’s Manual Model 6221: AMPL opens menu to set AMPL: (value) (Section 7). FREQ opens menu to set FREQ (frequency) (Section 7). MAIN menu The MAIN MENU is a direct access menu that is opened by pressing the MENU key. Menu items include CAL, TEST, SERIAL#, and BEEPER. See Section 1 of the Reference Manual for more information on these MAIN MENU items.
Model 6220/6221 User’s Manual Getting Started 1-15 Model 6220 menu navigation After entering a menu structure, use the editing keys as follows: Selecting menu items 1. 2. 3. Use the Cursor Keys to place the blinking cursor on a menu item to be opened or selected. Press the ENTER key to select an item or open a sub menu. Use the EXIT key to cancel a change or back out of the menu structure. Setting a value There are two ways to adjust a value: value adjust or numeric entry.
1-16 Getting Started Model 6220/6221 User’s Manual Model 6221 menu navigation Editing for the Model 6221 is basically the same as editing for the Model 6220, except for the following differences: • • • • Cursor control is provided by the Cursor Keys located under the rotary knob. When at a menu level that requires an item to be selected, the Rotary Knob can also be used for cursor control.
Model 6220/6221 User’s Manual Getting Started 1-17 Remote interface For remote operation, one of the following interfaces can be used: GPIB, RS-232, and (for the Model 6221) Ethernet. When using the GPIB, the SCPI or KI-220 lanuage can be used. NOTE Interface selection and configuration can be performed from the COMMUNICATIONS SETUP menu, which is accessed by pressing the COMM key. All details on interface selection and configuration are provided in Section 10 of the Reference Manual.
1-18 Getting Started Model 6220/6221 User’s Manual Default settings The Model 622x can be restored to one of seven setup configurations: five usersaved setups, PRESET (bench defaults), and *RST (bus defaults). As shipped from the factory, the Model 622x powers up to the PRESET settings. PRESET settings provide a general purpose setup for front panel operation, while the *RST settings do the same for remote operation.
Model 6220/6221 User’s Manual Getting Started 1-19 Select power-on setup Power-on to PRESET defaults: Press SETUP > Select POWER ON > Select PRESET Power-on to *RST defaults: Press SETUP > Select POWER ON > Select *RST Power-on to user setup: Press SETUP > Select POWER ON > Select USER SETUP NUMBER > Set memory location (0 to 4) > Press ENTER Remote programming SYSTem:POSetup ‘ Select power-on setup. ‘ = RST, PRESet, SAV0, SAV1, SAV2, SAV3, or ‘ SAV4.
1-20 Getting Started Model 6220/6221 User’s Manual Return to Section 1 topics
2 Output Connections Section 2 topics Output connectors, page 2-2 Triax connector, page 2-2 Ground points, page 2-3 LO and GUARD banana jacks, page 2-3 INTERLOCK, page 2-4 Output configurations, page 2-5 Triax inner shield, page 2-6 Triax output low, page 2-7 Guards, page 2-8 Triax Cable Guard, page 2-8 Floating the current source, page 2-9 Connections to DUT, page 2-9 Supplied triax cable, page 2-9 Basic connections, page 2-10 Shields and guarding, page 2-10 Using a test fixture, page 2-12 NOTE The infor
2-2 Output Connections Model 6220/6221 User’s Manual Output connectors Triax connector Current source output is accessed at the 3-lug female triax connector on the rear panel. Use a 3-slot male triax cable to make connections to this connector. A triax cable terminated with alligator clips (Model 237-ALG-2) is a supplied item for the Model 622x (see “Supplied triax cable” on page 2-9). The triax connector is shown in Figure 2-1.
Model 6220/6221 User’s Manual Output Connections 2-3 shield connection setting. See “Triax Cable Guard” on page 2-8 for details on using the Cable Guard. Outer shield – The outer shield of the triax connector is always connected to Earth Ground of the Model 622x (see “Ground points” for details). Frequency variable resistor (FVR) The outer shield (Earth Ground) of the triax connector is isolated from the chassis of the Model 622x by a Frequency Variable Resistor (FVR).
2-4 Output Connections Model 6220/6221 User’s Manual GUARD banana jack The GUARD available at the banana jack is different from CABLE GUARD that can be accessed at the triax cable. See “Guards” on page 2-8 for more information. INTERLOCK The Model 622x is equipped with an INTERLOCK that is to be connected to an interlock switch (see Figure 2-3). When the interlock switch is open, the OUTPUT of the Model 622x is disabled and cannot be turned on.
Model 6220/6221 User’s Manual Output Connections 2-5 Output configurations There are four configurations that can be used for current source output: • Triax inner shield is connected to Output Low, which is connected to Earth Ground (see Figure 2-4A). Triax inner shield is connected to Cable Guard and Output Low is connected to Earth Ground (see Figure 2-5A). Triax inner shield is connected to Output Low, which is disconnected from Earth Ground (Floating) (see Figure 2-4B). This is the default setting.
2-6 Output Connections Model 6220/6221 User’s Manual Figure 2-5 Output configurations – triax inner shield connected to Cable Guard A) Triax Output Low setting: Earth Ground 62xx OUTPUT 105Vpk Max 105Vpk Max Earth Ground FVR 2 Chassis Output High (red)1 B) Triax Output Low setting: Floating 62xx OUTPUT Cable Guard (black)1 Output Low (Earth Ground) (green)1 1) Boot color for alligator clip if using supplied triax cable. 2) Frequency Variable Resistor (FVR). See Figure 2-1.
Model 6220/6221 User’s Manual Output Connections 2-7 Commands for triax inner shield connection: OUTPut:ISHield? OUTPut:ISHield ‘ Query connection for triax inner shield. ‘ Connect inner shield to Cable Guard or Output Low.
2-8 Output Connections Model 6220/6221 User’s Manual Guards The Model 622x provides two guards: triax Cable Guard and banana jack Guard. Cable Guard – This guard provides a voltage that is at essentially the same potential as Output High of the Model 622x. Guarding may greatly reduce leakage current and capacitance in the test circuit. Effective guarding requires that the triax Cable Guard configuration be used for the triax cable and a guard plate be used for the DUT.
Model 6220/6221 User’s Manual Output Connections 2-9 When to use Cable Guard When to use Cable Guard is a judgement call that must be made by the user. In general, Cable Guard is used to reduce leakage current for high-impedance DUT, and reduce capacitance in the triax cable and at the DUT to improve output response (rise time). Lower capacitance results in faster output response.
2-10 Output Connections Model 6220/6221 User’s Manual Basic connections Basic connections can be used for low voltage (not greater than 30Vrms, 42Vpeak) testing where guarding and/or noise shielding are not required. Basic connections to a DUT are shown in Figure 2-6. Use the connections shown in Figure 2-6A if the inner shield of the triax connector is connected to Output Low. Use the connections shown in Figure 2-6B if the inner shield is connected to Cable Guard.
Model 6220/6221 User’s Manual Output Connections 2-11 Safety shield connections A safety shield must be used whenever hazardous voltages (>30Vrms, 42Vpeak) will be present. The metal safety shield must completely surround DUT test circuitry and must be connected to a known Safety Earth Ground and Chassis (see Figure 2-8). Use #18AWG wire or larger for connections.
2-12 Output Connections Model 6220/6221 User’s Manual A safety shield must be used whenever hazardous voltages (>30Vrms, 42Vpeak) will be present in the test circuit. Figure 2-10 shows how to make guarded connections with the use of a safety shield. Using shielding and guarding together Figure 2-10 shows connections for a test system that uses a noise shield, a safety shield, and guarding.
3 DC Current Source Operation Section 3 topics Current source output capabilities, page 3-2 Source ranges, page 3-2 Compliance, page 3-3 Output power (source or sink), page 3-3 Output response, page 3-5 Setting source and compliance, page 3-8 Source and compliance editing, page 3-8 Sourcing current, page 3-12 Remote programming – source output commands, page 3-15 NOTE The information in this section is an abbreviated version of the information in Section 3 of the Reference Manual.
3-2 DC Current Source Operation Model 6220/6221 User’s Manual Current source output capabilities • • • • Nine ranges to source current from 100fA to 105mA. Compliance can be set from 0.1V to 105V in 10mV steps. Maximum output power is 11W. Four quadrant (source and sink) source operation Source ranges Each source range has 5% overrange capability. Each source range and its maximum output is listed in Table 3-1. A source range can be selected manually, or autorange can be used.
Model 6220/6221 User’s Manual DC Current Source Operation 3-3 Compliance The compliance setting limits the output voltage of the Model 622x. The voltage compliance limit can be set from 0.1V to 105V in 10mV steps. The output will not exceed the programmed compliance level. Make sure to set compliance to a voltage level that is greater than the voltage requirements for the load. For example, if sourcing 10mA to a 1kΩ load, the voltage compliance setting must be >10V (10mA x 1kΩ = 10V).
3-4 DC Current Source Operation Model 6220/6221 User’s Manual When operating as a sink, the Model 622x is dissipating power rather than sourcing it. The polarity of the current and voltage seen at the output is opposite (one positive, one negative). An external source or an energy storage device, such as a capacitor, can force operation into the sink region. Figure 3-1shows examples of the Model 622x connected to an external source where it can operate as a source or sink.
Model 6220/6221 User’s Manual DC Current Source Operation 3-5 Figure 3-2 Output boundaries (source and sink) +I 105mA Quadrant IV Sink -V Quadrant I Source -105V 105V Quadrant III Source +V Quadrant II Sink -105mA -I Output response Output response is the time it takes for an output change to settle to within 1% of its final value. For the Model 6220, output response (settling time) can be as fast as 100µs (typical).
3-6 DC Current Source Operation Model 6220/6221 User’s Manual For example, assume the Model 6221 is on the 2mA range and FAST response is selected. For this configuration, the Settling Time is specified at 2µs (typical). Also assume the load impedance is 1kΩ. With the analog filter enabled, the additional settling time (five time constants) is calculated as follows: Additional settling time = 5RC = 5 x 1kΩ x 33pF = 0.165µs Enabling the analog filter adds 0.
Model 6220/6221 User’s Manual DC Current Source Operation 3-7 Response speed setting (6221 only) The filter response speed of the Model 6221 can be set for FAST or SLOW. For the SLOW setting, the output response of the Model 6221 is the same as the output response of the Model 6220. The FAST setting allows a faster output response. The FAST response setting changes the maximum output response bandwidth of the Model 6221 to 1MHz. It also reduces stability.
3-8 DC Current Source Operation Model 6220/6221 User’s Manual Setting source and compliance Source and compliance editing from the front panel cannot be performed from the front panel if the Model 622x is in remote. To return to the local state, press the LOCAL key. For remote programming, commands to select source range, and set source and compliance values are shown in Table 3-2. Programming examples are also provided in the procedure for “Sourcing current” on page 3-12.
Model 6220/6221 User’s Manual DC Current Source Operation 3-9 Source/compliance editing notes The following notes apply to source editing for both the Models 6220 (Figure 3-3) and 6221 (Figure 3-4): 1. The displayed source and/or compliance value can only be edited if the DC source mode is selected. 2. Select a fixed range that will accommodate the source value to be set.
3-10 DC Current Source Operation Model 6220/6221 User’s Manual Figure 3-4 Source and compliance editing – Model 6221 DC Output Select Key EDIT key Rotary Knob & Cursor Keys EDIT/ LOCAL DC RANGE AUTO Numeric Entry Keys 0 1 2 3 4 5 6 7 8 9 +/ 0000 ENTER / EXIT Keys EXIT Range Keys RANGE PUSH TO ENTER CURSOR ENTER Select next higher fixed range. Select best fixed range. Select next lower fixed range. Perform the following steps to set source and compliance values for the Model 6221.
Model 6220/6221 User’s Manual DC Current Source Operation 3-11 Autorange Front panel operation The AUTO range key is a single action control to select the best fixed range for the displayed source value. After setting a source value, pressing AUTO will ensure that the best fixed range is selected. For example, assume the source is set to +1mA on the 20mA range (+01.000 mA displayed). When the AUTO key is pressed, the range will change to the 2mA range (which is the best range).
3-12 DC Current Source Operation Model 6220/6221 User’s Manual Source preset The PRES key can be used to set the source to a preset value and range. When the PRES key is pressed, the source will select the preset range and set the preset value. The preset value is set as follows: 1. 2. Press the PRES key. The message “PRES” is displayed while the preset value is being used. Using the source editing keys as explained in Figure 3-3 and Figure 3-4, set the preset value to the desired level.
Model 6220/6221 User’s Manual DC Current Source Operation 3-13 Remote programming – Autorange can be used when setting the I-source value. With autorange enabled, the Model 622x will automatically select the optimum (lowest) range to accommodate the source value. The commands to select the source range, and set the output and compliance values are provided in Table 3-2. The following examples demonstrate proper syntax.
3-14 DC Current Source Operation Model 6220/6221 User’s Manual Example – Enables the analog filter and, for the Model 6221, sets the output response to fast: CURRent:FILTer ON OUTPut:RESPonse FAST 4. ‘ Enables the analog filter. ‘ Sets the output response of the 6221 to FAST. Turn on the output. NOTE In order to turn on the output, an interlock switch must be connected to the INTERLOCK connector on the rear panel of the Model 622x.
Model 6220/6221 User’s Manual DC Current Source Operation 3-15 Remote programming – source output commands Table 3-2 lists the commands to configure and control the DC output. A programming example to output DC current is also provided. Table 3-2 DC output commands Command CLEar CURRent:RANGe CURRent:RANGe:AUTO CURRent CURRent:COMPliance CURRent:FILTer OUTPut:RESPonse OUTPut SourceMeter Description Default Turns output off and sets output level to zero.
3-16 DC Current Source Operation Model 6220/6221 User’s Manual Programming example The following programming example shows a typical command sequence to configure and control the DC output: CLEar CURRent:RANGe:AUTO ON CURRent 12e-3 CURRent:COMPliance 10 OUTPut ON OUTPut OFF ‘ ‘ ‘ ‘ ‘ ‘ Turns the output off. Enables autorange. Sets output level to +12mA. Sets voltage compliance to 10V. Turns the output on. Turns the output off. Applications Some applications for the Model 622x are summarized below.
4 Sweeps Section 4 topics Sweep overview, page 4-2 Linear staircase sweep, page 4-2 Logarithmic staircase sweep, page 4-2 Custom sweep, page 4-2 Sweep characteristics, page 4-4 Custom sweep editing, page 4-4 Using auto-copy with custom sweeps, page 4-4 Source ranging, page 4-4 Sweep delay, page 4-5 Front panel sweep operation, page 4-5 Using the sweep configuration menu, page 4-5 Performing a staircase sweep, page 4-6 Running a staircase sweep, page 4-9 Remote sweep operation, page 4-8 Running a staircase
4-2 Sweeps Model 6220/6221 User’s Manual Sweep overview As shown in Figure 4-1, the Model 622x Current Source can generate three types of DC current sweeps. NOTE User setups cannot be saved or recalled while a sweep is armed or running. Attempting to do so will generate error +413 Not allowed with mode arm. Linear staircase sweep With this sweep type, the current increases or decreases in specific steps, beginning with a start current and ending with a stop current.
Model 6220/6221 User’s Manual Sweeps Figure 4-1 Comparison of sweep types A. Linear Staircase Sweep 5mA (Stop) 4mA 3mA 2mA 1mA Start Bias 0mA B. Logarithmic Staircase Sweep Stop 100mA 10mA Logarithmic scale shown for staircase steps. 1mA 0.1mA Bias Start 0mA C.
4-4 Sweeps Model 6220/6221 User’s Manual Sweep characteristics NOTE Jitter – Step-to-step sweep timing may jitter as much as 1ms. This jitter can be eliminated by disabling the front panel. For details, see “Step-to-step timing jitter” on page 1-12. Custom sweep editing A typical custom sweep editing display is shown below: P12345: +1.234567 mA Del:123456.789s Cmpl:100.00 V The leftmost value on the top line is the point number, and the next value is the actual current setting.
Model 6220/6221 User’s Manual Sweeps 4-5 Sweep delay The sweep delay parameter determines how long the Model 622x will remain on each sweep step once the output current is set to the step value. For linear and logarithmic staircase sweeps, the sweep delay period is the same for every step in the sweep. For customs sweeps, the sweep delay for each step can be independently programmed. The programmable range for the sweep delay is from 0.001s to 999999.999s.
4-6 Sweeps Model 6220/6221 User’s Manual Performing a staircase sweep 1. Configure source functions: a. If desired, set the bias current (output current prior to the start of the sweep) by pressing the DC key and then setting the current to the desired value. b. Select the compliance display field, then set the voltage compliance as appropriate for expected sweep parameters. 2. Configure the sweep as follows: a. Press CONFIG then SWP to enter the sweep configuration menu. b.
Model 6220/6221 User’s Manual Sweeps 4-7 Performing a custom sweep 1. Configure the bias current (output current prior to the start of the sweep) by pressing the DC key and then setting the current to the desired value. 2. Configure the sweep as follows: a. Press CONFIG then SWP to enter the sweep configuration menu. b. Select TYPE, then press ENTER. c. Select CUSTOM, then press ENTER to choose a custom sweep. d. Select #-POINTS, press ENTER, then enter the number of sweep points (64,000 maximum). e.
4-8 Sweeps Model 6220/6221 User’s Manual Remote sweep operation Procedures for programming and running a sweep are shown on the following pages. Each of these procedures includes commands for a typical sweep example. Table 4-2 summarizes parameters for each of these examples. See “SCPI commands — sweeps,” page 4-11 for listings of sweep commands.
Model 6220/6221 User’s Manual Sweeps 4-9 Running a staircase sweep 1. Configure source functions. Examples – The following commands restore defaults, set the bias current to 100μA, and the compliance to 10V: *RST SOUR:CURR 1e-4 SOUR:CURR:COMP 10 2. Configure the sweep.
4-10 Sweeps Model 6220/6221 User’s Manual Running a custom sweep 1. Configure source functions. Examples – The following commands restore defaults and set the bias current to 50μA: *RST SOUR:CURR 5e-5 2. Configure the sweep.
Model 6220/6221 User’s Manual Sweeps 4-11 SCPI commands — sweeps Commands for linear and logarithmic staircase sweeps are listed in Table 4-3, while commands for custom (list) sweeps are listed in Table 4-4. Table 4-3 Staircase sweep commands (linear and logarithmic) Command Description Default SOURce[1]:CURRent:STARt Sets start current. = -0.105 to 0.105 (A) 0 SOURce[1]:CURRent:STOP Sets stop current. = -0.105 to 0.105 (A) 0.1 SOURce[1]:CURRent:STEP Sets step current.
4-12 Sweeps Model 6220/6221 User’s Manual Table 4-4 Custom (list) sweep commands Command Description SOURce[1]:LIST:CURRent [,, ...] Defines list of currents. = -0.105 to 0.105 (A) SOURce[1]:LIST:CURRent:APPend [,, ...] Adds current points to existing list. = -0.105 to 0.105 (A) SOURce[1]:LIST:DELay [,, ...] Defines list of delay values. = 0 to 999.9999 (s) SOURce[1]:LIST:DELay:APPend [,, ...
5 Delta, Pulse Delta, and Differential Conductance Section 5 topics Operation overview, page 5-2 Test systems, page 5-4 Keithley instrumentation requirements, page 5-4 System configurations, page 5-4 System connections, page 5-5 DUT test connections, page 5-8 Configuring communications, page 5-9 Triggering sequence, page 5-10 Readings, page 5-11 Display readings, page 5-11 Measurement units, page 5-11 Read commands, page 5-13 Delta, page 5-13 Model 622x measurement process, page 5-13 Configuration setting
5-2 Delta, Pulse Delta, and Differential Conductance Model 6220/6221 User’s Manual Operation overview The Model 6220 or 6221 Current Source can be used with a Model 2182/2182A Nanovoltmeter to perform Delta and Differential Conductance. The Model 6221/2182A combination can also perform Pulse Delta. These operations use a delta current-reversal technique to cancel the effects of thermal EMFs.
Model 6220/6221 User’s Manual Delta, Pulse Delta, and Differential Conductance Figure 5-1 Delta, Pulse Delta, and Differential Conductance measurements A) Delta measurements 2182/2182A A/D 2182/2182A A/D 2182/2182A A/D I-High DELTA Reading 1st 622x 0 I-Source DELTA DELTA Reading 3rd Reading 2nd DELTA Reading 4th I-Low 2182/ 2182/ 2182A 2182A A/D A/D 1st Delta Cycle 2nd Delta Cycle 2182/ 2182A A/D 3rd Delta Cycle 4th Delta Cycle B) Pulse Delta measurements 2182A A/D 2182A A/D 2182A A/D I-High
5-4 Delta, Pulse Delta, and Differential Conductance Model 6220/6221 User’s Manual Test systems NOTE Supplied example software allows you to control Model 622x delta tests from any PC using simple mouse-clicks through a virtual front panel. For details, see “Using the example software” in Section 10 of the Reference Manual.
Model 6220/6221 User’s Manual Delta, Pulse Delta, and Differential Conductance 5-5 Serial communications In order to perform Delta, Pulse Delta, or Differential Conductance measurements, the Model 622x must communicate to the Model 2182/2182A over the serial (RS-232) interface. With serial communications properly configured and connected, the Model 622x will automatically send setup commands to the Model 2182/2182A when Delta, Pulse Delta, or Differential Conductance is armed.
5-6 Delta, Pulse Delta, and Differential Conductance Model 6220/6221 User’s Manual Trigger Link – The Trigger Link synchronizes triggering between the Current Source and the Nanovoltmeter. Trigger Link connections assume that the Model 2182/2182A is using the factory default (hard-wired) configuration: EXT TRIG (input) = line #2 VMC (output) = line #1) Delta, Pulse Delta, and Differential Conductance will not work if the Model 2182/2182A is not using the default Trigger Link configuration.
Model 6220/6221 User’s Manual Delta, Pulse Delta, and Differential Conductance Figure 5-4 System connections – PC control of Model 622x Keithley 622x Current Source Keithley 2182/2182A Nanovoltmeter 6220: GPIB selected 6221: GPIB or Ethernet selected iEEE-488 ETHERNET RS-232 RS-232 On TRIGGER LINK TRIGGER LINK RS-232 Cable (null-modem, male-to-male) 8501 Trigger Link Cable IEEE-488 Cable OR Ethernet Cross-over Cable (RJ-45 male/male) (6221only) PC Return to Section 5 topics RS-232 iEEE-488
5-8 Delta, Pulse Delta, and Differential Conductance Model 6220/6221 User’s Manual DUT test connections WARNING Before making or breaking test connections, the Models 622x and 2182/2182A must be turned off and the line cords must be disconnected from AC line power. DUT test connections are shown in Figure 5-5. This connection scheme uses Cable Guard and an earth grounded test fixture that is equipped with an interlock switch. See Section 2 of this manual for connection information.
Model 6220/6221 User’s Manual Delta, Pulse Delta, and Differential Conductance 5-9 Configuring communications For both front panel and remote operation, the RS-232 of the Model 2182/2182A must be enabled (on), and the selected communications interface for the Model 622x must be the GPIB or the Ethernet (Model 6221 only).
5-10 Delta, Pulse Delta, and Differential Conductance Model 6220/6221 User’s Manual Arming and Starting the Test Arming – After a delta test is configured, the test is armed by pressing the DELTA key, PULSE key (Pulse Delta), or COND key (Differential Conductance).
Model 6220/6221 User’s Manual Delta, Pulse Delta, and Differential Conductance 5-11 Readings Display readings Display reading examples: +1.23456 nV Delta Delta voltage reading +1.23456 Ω Delta Delta ohms reading +1.23456 S D Cond Differential Conductance Siemens reading +1.23456 mWp Pulse Pulse Delta peak power (Watts) reading 1, 2, 3 +1.23456 mW Pulse Pulse Delta average power (Watts) reading 1, 2, 3 1.
5-12 Delta, Pulse Delta, and Differential Conductance Model 6220/6221 User’s Manual The default units for the Model 622x is volts. With Ohms (Ω) units or Siemens (S) units selected, a reading is calculated as follows: Ω = V/I S = I/V Where: V is the Delta, Pulse Delta, or Differential Conductance voltage reading. I is the current sourced by the Model 622x.
Model 6220/6221 User’s Manual Delta, Pulse Delta, and Differential Conductance 5-13 Read commands The Model 622x does not perform measurements. However, raw readings are sent from the Model 2182/2182A to the Model 622x to calculate Delta, Pulse Delta, or Differential Conductance readings. Readings from the Model 2182/ 2182A are processed, stored, and displayed by the Model 622x. The following read commands return pre-math readings and buffer readings.
5-14 Delta, Pulse Delta, and Differential Conductance Model 6220/6221 User’s Manual Figure 5-6 Delta measurement technique 2182/2182A A/D A 2182/2182A A/D C 2182/2182A A/D E DELTA Reading 1st DELTA Reading 3rd I-High 622x 0 I-Source DELTA Reading 2nd time DELTA Reading 4th I-Low 2182/ 2182A A/D B 1st Delta Cycle 2182/ 2182A A/D D 2182/ 2182A A/D F 2nd Delta Cycle 3rd Delta Cycle 4th Delta Cycle A - 2B + C 1st Delta Reading = 4 ( 2nd Delta Reading = ) · (-1) 0 ( B - 2C4 + D ) · (-1)1 3rd
Model 6220/6221 User’s Manual Delta, Pulse Delta, and Differential Conductance 5-15 Measurement units The fundamental measurement for Delta is voltage (Volts; V). However, the voltage reading can converted into a conductance (Siemens; S), resistance (Ohms; Ω), or power (Watts; W) reading. See page 5-11 for details on selecting “Measurement units”. Configuration settings Delta settings from the front panel are described as follows.
5-16 Delta, Pulse Delta, and Differential Conductance Model 6220/6221 User’s Manual Operation Delta operation – front panel The system configuration for front panel stand-alone operation is shown in Figure 5-2A on page 5-5. 1. Connections are shown in the following illustrations. All power must be removed from all components in the system before making connections: • Figure 5-3, page 5-6 – System connections • Figure 5-5, page 5-8 – DUT test connections 2.
Model 6220/6221 User’s Manual Delta, Pulse Delta, and Differential Conductance 5-17 8. When finished, press EXIT to disarm Delta. 9. On the Model 622x, press RECALL to access the Delta readings stored in the buffer. Operation – PC control The system configuration for PC control of the Model 622x is shown in Figure 5-2B. 1. Connections are shown in the following illustrations.
5-18 Delta, Pulse Delta, and Differential Conductance Model 6220/6221 User’s Manual Examples – The following commands demonstrate proper syntax for sending commands and returning responses to queries over the serial port: SYST:COMM:SER:SEND “VOLT:RANG 2” SYST:COMM:SER:SEND “VOLT:RANG?” SYST:COMM:SER:ENT? SYST:COMM:SER:SEND “VOLT:NPLC 1” SYST:COMM:SER:SEND “VOLT:NPLC?” SYST:COMM:SER:ENT? 4. Select 2V range for 2182/ 2182A. Send range query. Return response to query.
Model 6220/6221 User’s Manual 6. Delta, Pulse Delta, and Differential Conductance 5-19 Read Delta readings – While Delta is running, the latest Model 2182/2182A Delta reading can be read by the Model 622x using the following command: ‘ Reads the latest Delta reading. SENS:DATA? The above read command reads the last Delta reading that was performed by the Model 2182/2182A. If this command is sent before a new reading is available, the last Delta reading will again be returned.
5-20 Delta, Pulse Delta, and Differential Conductance Model 6220/6221 User’s Manual Table 5-2 Delta commands Command Description [SOURce[1]]:DELTa:NVPResent? Queries connection to 2182A. 1 = yes, 0 = no Default 1 [SOURce[1]]:DELTa:HIGH Sets high source value (amps). 2 = 0 to 105e-3 [SOURce[1]]:DELTa:LOW Sets low source value (amps). 2 = 0 to -105e-3 [SOURce[1]]:DELTa:DELay Sets Delta delay (seconds). 2 = 0 to 9999.
Model 6220/6221 User’s Manual Delta, Pulse Delta, and Differential Conductance 5-21 Pulse Delta Use the Keithley Model 2182A with the Model 6221 to run Pulse Delta. Model 6221 measurement process Pulse Delta measurements For Pulse Delta, the Model 6221 outputs current pulses. Current pulses that have a short pulse width are ideal to test a low-power DUT that is heat sensitive. By default, Pulse Delta uses a 3-point repeating-average algorithm to calculate readings.
5-22 Delta, Pulse Delta, and Differential Conductance Where: Model 6220/6221 User’s Manual Y is the measurement at the high pulse. X is the measurement at the first low pulse. Measurement units The fundamental Pulse Delta measurement explained above is in volts. The reading can instead be converted into Ohms (W), Siemens (S), or Power (W). Details on selecting “Measurement units” are provided on page 5-11.
Model 6220/6221 User’s Manual Delta, Pulse Delta, and Differential Conductance 5-23 Like the Fixed output shown in Figure 5-8, a Sweep output is synchronized to the frequency of the power line voltage, and the pulse width is adjustable and is the same for all pulses. The three available sweeps include (1) staircase sweep, (2) logarithmic sweep, and (3) custom sweep. Examples of these Sweep outputs are shown in Figure 5-9. Staircase sweep – Figure 5-9A shows an example of a staircase Sweep output.
5-24 Delta, Pulse Delta, and Differential Conductance Model 6220/6221 User’s Manual Figure 5-8 Pulse timing One Pulse Delta Cycle 5, 6 (Interval = 5 PLC) Pulse Width 3 I-High 1 Pulse Width 3 I-Low 2 Low One Line Cycle 4 Pulse Width 3 High Low One Line Cycle 4 One Line Cycle 4 One Line Cycle 4 Power Line Voltage 1. 2. 3. 4. I-High can be set from -105mA to +105mA (default is 1mA). I-Low can be set from -105mA to +105mA (default is 0mA).
Model 6220/6221 User’s Manual Delta, Pulse Delta, and Differential Conductance 5-25 Figure 5-9 Pulse sweep output examples A) Staircase sweep pulse train: 2 to 10mA in 2mA steps Linear Scale Step = 2mA (set by the user) 10mA Stop 10mA 8mA Step 6mA Step 4mA Step 2mA Start 2mA Low 0mA LO HI Step LO LO One Pulse Delta Cycle (Sweep Delay) HI LO LO One Pulse Delta Cycle (Sweep Delay) HI LO LO One Pulse Delta Cycle (Sweep Delay) HI LO LO One Pulse Delta Cycle (Sweep Delay) HI LO On
5-26 Delta, Pulse Delta, and Differential Conductance Model 6220/6221 User’s Manual Duty Cycle Duty cycle defines the ratio between pulse “on” time and pulse “off” time during a Pulse Delta cycle. For example, for a 25% duty cycle, the pulse would be “on” (high) for one-quarter of the cycle, and “off” (0mA low) for three-quarters of the cycle. Pulse Delta cycles with a short duty-cycle can be sourced to prevent heat from adversely affecting the measurement of low power DUT.
Model 6220/6221 User’s Manual Delta, Pulse Delta, and Differential Conductance 5-27 Fixed output settings The following parameters are set from the CONFIG PULSE DELTA menu that is accessed by pressing the CONFIG key and then the PULSE key. I-Hi and I-Lo These settings specify the high and low level of the pulses. Each high pulse returns to the programmed low pulse level. Both I-Hi and I-Lo can be set from -105mA to +105mA. The default setting for I-Hi is +1mA, and the default for I-Lo is 0mA.
5-28 Delta, Pulse Delta, and Differential Conductance Model 6220/6221 User’s Manual Interval The Pulse Delta cycle time period (interval) is expressed as a number of power line cycles (PLC). For 60Hz one PLC is 16.667ms, and for 50Hz, one PLC is 20ms. Interval can be set from 5 PLC (default setting) to 999999 PLC. Sweep The sweep function of the Model 6221 can be enabled (YES) or disabled (NO).
Model 6220/6221 User’s Manual Delta, Pulse Delta, and Differential Conductance 5-29 Operation Pulse Delta operation – front panel The system configuration for front panel stand-alone operation is shown in Figure 5-2A on page 5-5. 1. Connections are shown in the following illustrations. All power must be removed from all components in the system before making connections: • Figure 5-3, page 5-6 – System connections • Figure 5-5, page 5-8 – DUT test connections 2.
5-30 Delta, Pulse Delta, and Differential Conductance Model 6220/6221 User’s Manual To set the measurement units, press the UNITS key to display the READING UNITS menu. Select VOLTS, OHMS, WATTS, or SIEMENS. When WATTS is selected, you will then be prompted to select the power units type: AVERAGE or PEAK. Measurement units can be changed while Pulse Delta is running. 6. On the Model 622x, press the PULSE key to arm Pulse Delta.
Model 6220/6221 User’s Manual Delta, Pulse Delta, and Differential Conductance 5-31 The following query command is used to return the response to a query command sent over the serial port: SYSTem:COMMunicate:SERial:ENTer? When communicating over the serial port, there are no errors reported if a Model 2182A is not connected to the serial port.
5-32 Delta, Pulse Delta, and Differential Conductance B. 6. Model 6220/6221 User’s Manual The initiate command starts Pulse Delta readings. After the specified finite number of Pulse Delta readings are performed, Pulse Delta will stop running. At this point another initiate command will re-start Pulse Delta. New Pulse Delta readings will overwrite the old Pulse Delta readings in the Model 6221 buffer. If the Infinity count is set, Pulse Delta will run continuously.
Model 6220/6221 User’s Manual Delta, Pulse Delta, and Differential Conductance 5-33 Table 5-3 Pulse Delta commands Command Description Default 1 SOURce[1]:PDELta:NVPResent? Queries if 2182A is connected. 1 = yes, 0 = no SOURce[1]:PDELta:HIGH Sets high pulse value (amps). 2 = -105e-3 to 105e-3 1e-3 SOURce[1]:PDELta:LOW Sets low pulse value (amps). 2 = -105e-3 to 105e-3 0 SOURCe[1]:PDELta:WIDTh Sets pulse width (seconds).
5-34 Delta, Pulse Delta, and Differential Conductance Model 6220/6221 User’s Manual When using Sweep output, use the SOUR:DEL command to set the Pulse Delta cycle time period (in seconds) for a linear or log sweep. For a custom sweep, use the SOUR:LIST:DEL command to cycle time (in seconds). See Section 4 for details on sweeps. 4. When using a Fixed output, use the SOUR:PDEL:RANG command to set the source range. When using a Sweep output, use the SOUR:SWE:RANG command to set range. 5.
Model 6220/6221 User’s Manual Delta, Pulse Delta, and Differential Conductance 5-35 Figure 5-10 Differential Conductance measurement process 70µA 60µA Step Stop 50µA dV Calc #5 A/D Rdg G A/D Rdg = 2182/2182A voltage measurement conversion. dV Calc = Calculate differential voltage (dV) using last three A/D Rdgs.
5-36 Delta, Pulse Delta, and Differential Conductance Model 6220/6221 User’s Manual Differential Conductance calculations dV calculations While the dV calculations for the first six dV readings are shown in Figure 5-10, the following formula can be used to calculate any dV reading in the test: (X – Y) (Z – Y) ------------------ + -----------------n 2 2 dV = -------------------------------------------- • ( – 1 ) 2 Where: X, Y, and Z are the three A/D measurements for a dV reading.
Model 6220/6221 User’s Manual Delta, Pulse Delta, and Differential Conductance 5-37 Measurement units The fundamental measurement for Differential Conductance is differential voltage (dV). However, the dV reading can be converted into a differential conductance (dG), differential resistance (dR), or power (Watts) reading. See page 5-11 for details on selecting “Measurement units”.
5-38 Delta, Pulse Delta, and Differential Conductance Model 6220/6221 User’s Manual Delay – The delay for Differential Conductance is used to allow the current source to settle when the output changes to the next stepped delta level. This delay occurs after a trigger from the Model 2182/2182A is received. Delay can be set from 1ms to 9999.999s. The default delay setting is 2ms.
Model 6220/6221 User’s Manual 6. 7. 8. 9. Delta, Pulse Delta, and Differential Conductance 5-39 To set the measurement units, press the UNITS key to display the READING UNITS menu. Select VOLTS, OHMS, WATTS, or SIEMENS. Measurement units can be changed while Differential Conductance is running. On the Model 622x, press the COND key to arm Differential Conductance. The Model 6221 is armed when the message “DIFF COND ARMED Press TRIG to start” is displayed briefly and the ARM annunciator turns on.
5-40 Delta, Pulse Delta, and Differential Conductance Model 6220/6221 User’s Manual The following query command is used to return the response to a query command sent over the serial port: SYSTem:COMMunicate:SERial:ENTer? When communicating over the serial port, there are no errors reported if a Model 2182/2182A is not connected to the serial port.
Model 6220/6221 User’s Manual A. B. 6. Delta, Pulse Delta, and Differential Conductance 5-41 Trace points specifies the size of the buffer. Buffer size should be the same value as the number of Differential Conductance readings in the test. See Section 6 for details on all buffer commands. The initiate command starts Differential Conductance readings. After all Differential Conductance readings are performed, Differential Conductance will stop running.
5-42 Delta, Pulse Delta, and Differential Conductance Model 6220/6221 User’s Manual Table 5-4 Differential Conductance commands Command Description SOURce[1]:DCONductance:NVPResent? Default Queries if 2182/2182A is connected. 1 1 = yes, 0 = no SOURce[1]:DCONductance:STARt Sets start value (amps). 2 = -105e-3 to 105e-3 -10e-6 SOURce[1]:DCONductance:STEP Sets step size (amps). 2 = 0 to 105e-3 1e-6 SOURce[1]:DCONductance:STOP Sets stop value (amps).
Model 6220/6221 User’s Manual Delta, Pulse Delta, and Differential Conductance 5-43 The query form for the arm command (SOUR:DCON:ARM?) is used determine if Differential Conductance is armed. A returned “1” indicates that Differential Conductance is armed. A “0” indicates that Differential Conductance is not armed. If the Model 6221 is already armed for another action (e.g., Delta or Pulse Delta), the Differential Conductance arm command will “un-arm” the other action and arm Differential Conductance. 4.
5-44 Delta, Pulse Delta, and Differential Conductance Return to Section 5 topics Model 6220/6221 User’s Manual
6 Averaging Filter, Math, and Buffer Section 6 topics Averaging filter, page 6-2 Averaging filter characteristics, page 6-2 Filter setup and control, page 6-4 Remote programming – Averaging filter, page 6-4 Math, page 6-7 mX+b and m/X+b (reciprocal), page 6-5 Configuring mX+b and m/X+b, page 6-6 Remote programming – Math, page 6-6 Buffer, page 6-7 Buffer characteristics, page 6-7 Storing readings, page 6-8 Recall, page 6-8 NOTE This section only applies to a Model 622x that is being used with a Model 218
6-2 Averaging Filter, Math, and Buffer Model 6220/6221 User’s Manual Averaging filter The average filter can be used with Delta, Pulse Delta, and Differential Conductance. There are two types of averaging filter: moving and repeating. “Filter type” is explained on page 6-3. The averaging filter stabilizes noisy delta measurements caused by noisy input signals.
Model 6220/6221 User’s Manual Averaging Filter, Math, and Buffer 6-3 Filter type There are two averaging filter types: moving and repeating. Moving filter Basic moving filter operation – For the moving filter, every delta reading yields a filtered delta reading. Every time a delta reading is placed in the buffer stack, the readings in the stack are averaged to yield a single filtered reading. The stack type is first-in, first-out. After the stack fills, the newest reading conversion replaces the oldest.
6-4 Averaging Filter, Math, and Buffer Model 6220/6221 User’s Manual Filter window The averaging filter uses a “noise” window to control filter threshold. As long as the signal remains within the selected window, A/D conversions continue to be placed in the stack. If the signal changes to a value outside the window, the filter resets, and the filtering process starts over.
Model 6220/6221 User’s Manual Averaging Filter, Math, and Buffer 6-5 Table 6-2 Averaging filter commands Command Description Default SENSe[1]:AVERage:TCONtrol Select filter control. = MOVing or REPeat. SENSe[1]:AVERage:WINDow Set filter window as % of range: = 0 to 10 (0 selects no window) SENSe[1]:AVERage:COUNt Specify filter count (size). = 2 to 300 SENSe[1]:AVERage[:STATe] Enable or disable averaging filter. MOV 0.
6-6 Averaging Filter, Math, and Buffer Model 6220/6221 User’s Manual Configuring mX+b and m/X+b To select and configure mX+b and m/X+b from the front panel, press CONFIG then MATH. Select the math function (MX+B or M/X+B), then enter the required parameters (m and b). Once a math function is selected, press the MATH key to toggle math on or off. The MATH annunciator will turn on to indicate that the math function is enabled.
Model 6220/6221 User’s Manual Averaging Filter, Math, and Buffer 6-7 Buffer The Model 622x has a buffer (data store) to store readings and related data elements for one to 65,536 buffer readings. Buffer readings are readings from the Model 2182/2182A that were processed by the Model 622x as delta readings (Delta, Pulse Delta, or Differential Conductance). Also stored are statistics for the readings. These include maximum, minimum, average mean, standard deviation, and peak-to-peak.
6-8 Averaging Filter, Math, and Buffer Model 6220/6221 User’s Manual Buffer statistics The following statistics are available on the stored buffer readings: • • • MIN and MAX provides the minimum and maximum readings stored in the buffer. It also indicates the buffer location of these readings. The PK-PK (peak-to-peak) value is the difference between the maximum and minimum readings stored in the buffer: PK-PK = MAX - MIN Mean is the mean average of the buffer readings.
Model 6220/6221 User’s Manual Averaging Filter, Math, and Buffer 6-9 Buffer statistics – While in buffer RECALL, use the EDIT/LOCAL key (see Figure 6-1). Each press of this key displays the next statistic. After the last statistic is displayed (Std Dev), pressing EDIT/LOCAL will display the stored readings. When finished, press EXIT to return to the normal display.
6-10 Averaging Filter, Math, and Buffer Model 6220/6221 User’s Manual Return to Section 6 topics
7 Wave Functions (6221 Only) Section 7 topics Wave function overview, page 7-2 Setting waveform parameters, page 7-3 Editing parameters, page 7-3 Amplitude and offset editing, page 7-3 Amplitude and units, page 7-3 Ranging, page 7-3 Range options, page 7-3 Arbitrary waveform ranging, page 7-4 Frequency, page 7-4 Offset, page 7-4 Duty cycle, page 7-5 Phase marker, page 7-6 Duration, page 7-7 Externally triggered waveforms, page 7-7 NOTE Front panel wave function operation, page 7-8 Using the wave function
7-2 Wave Functions (6221 Only) Model 6220/6221 User’s Manual Wave function overview Table 7-1 summarizes the basic characteristics of the four wave functions available in the Model 6221. More details on various aspects can be found in the following paragraphs. Table 7-1 Wave function characteristics Wave function Characteristics Sine wave Frequency: 1mHz to 100kHz Amplitude: 1pA to 105mA peak Range: 2nA to 100mA Offset: 0 to ±105mA Phase marker: 0° to 360° Duration: 100ns to 999999.
Model 6220/6221 User’s Manual Wave Functions (6221 Only) 7-3 Setting waveform parameters NOTE User setups cannot be saved or recalled while Wave is armed or running. Attempting to do so will generate error +413 Not allowed with mode arm. Editing parameters The AMPL and FREQ keys also function as left arrow and right arrow keys, respectively, when editing a numeric value or scrolling through a menu.
7-4 Wave Functions (6221 Only) Model 6220/6221 User’s Manual Arbitrary waveform ranging The arbitrary waveform is described in normalized units from -1 to +1. See the following example: Ranging: BEST Amplitude: 10mA peak Offset: 0mA ARB values: range from +1 to -1 These settings will generate a waveform with a peak-to-peak value of 20mA on the 20mA range. Frequency The frequency setting range for sine, square, ramp, and arbitrary waveforms is from 1mHz to 100kHz.
Model 6220/6221 User’s Manual Wave Functions (6221 Only) 7-5 Duty cycle For a square wave Figure 7-2A, the duty cycle setting is the portion of the total cycle that the wave is high relative to the period of the waveform. For a ramp waveform Figure 7-2B, the duty cycle corresponds to the fraction of the total wave cycle that is rising. A 50% duty cycle corresponds to a symmetric triangle wave.
7-6 Wave Functions (6221 Only) Model 6220/6221 User’s Manual Phase marker The phase marker (Figure 7-3) allows you to set a pulse marker that defines a specific point of a waveform over a range of 0 to 360°. The phase marker signal is a 1μs pulse that appears on the selected line of the external trigger connector (see information on the external trigger connector in Section 8 of the Model 622x Reference Manual for connector designations).
Model 6220/6221 User’s Manual Wave Functions (6221 Only) 7-7 Duration The duration setting defines how long the waveform is generated. You can set the duration in time over a range of 100ns to 999999.999s, in cycles from 0.001 to 99999999900 cycles (provided the equivalent time, cycles/frequency does not exceed the upper time duration limit), or choose a continuous waveform (INFinite setting). From the front panel, you can only specify a time duration from 0.001s to 999999.
7-8 Wave Functions (6221 Only) Model 6220/6221 User’s Manual Front panel wave function operation Using the wave function menu To configure wave functions, press CONFIG then WAVE, then make your selections from Table 7-2 below. See the detailed procedures for each wave function type that follow. Table 7-2 Wave function configuration menu Menu selection Description TYPE SINE SQUARE RAMP ARBx Select waveform type: Select sine wave. Select square wave. Select ramp wave. Select user-defined arbitrary wave.
Model 6220/6221 User’s Manual Wave Functions (6221 Only) Table 7-2 (cont.) Wave function configuration menu Menu selection MORE Description Expand to show additional menu items: TRIG-MODE MAN/BUS NONE TLNK-#1 #2 #3 #4 #5 #6 Configure low jitter external waveform triggering: 2 Disable external trigger mode (default). Enables external trigger mode with no line selected. Enables external trigger on trigger link line 1. Enables external trigger on trigger link line 2.
7-10 Wave Functions (6221 Only) Model 6220/6221 User’s Manual Generating a sine wave 1. If you intend to use fixed ranging, manually set the range high enough to accommodate both the amplitude and offset setting. 2. Configure the waveform as follows: a. Press CONFIG then WAVE to enter the wave function configuration menu. b. Select TYPE, then press ENTER. c. Select SINE, then press ENTER to choose a sine wave. d.
Model 6220/6221 User’s Manual Wave Functions (6221 Only) 7-11 Generating an arbitrary waveform NOTE Arbitrary waveforms cannot be defined from the front panel, but they can be generated once they are defined by using the procedure below. 1. If you are using the fixed range setting, manually set the range to a high enough setting to accommodate the expected amplitude and offset settings. 2. Configure the waveform as follows: a. Press CONFIG then WAVE to enter the wave function configuration menu. b.
7-12 Wave Functions (6221 Only) Model 6220/6221 User’s Manual Remote wave function operation Procedures for programming and generating waveforms for sine and arbitrary waveform types are given on the following pages. Each of these procedures includes commands for a typical wave function example. Table 7-3 summarizes parameters for each of these examples. See “SCPI commands — wave functions,” page 7-15 for a listing of wave function commands.
Model 6220/6221 User’s Manual Wave Functions (6221 Only) 7-13 Programming sine waves 1. Restore defaults with this command: *RST 2. Configure the waveform. Examples – The following commands configure a 1kHz sine wave with an amplitude of 10mA, 1mA offset, and phase marker off: SOUR:WAVE:FUNC SIN SOUR:WAVE:FREQ 1e3 SOUR:WAVE:AMPL 1e-2 SOUR:WAVE:OFFS 1e-3 SOUR:WAVE:PMAR:STAT OFF SOUR:WAVE:DUR:TIME 5 SOUR:WAVE:RANG BEST 3. Select sine wave. Set frequency to 1kHz. Set amplitude to 10mA.
7-14 Wave Functions (6221 Only) Model 6220/6221 User’s Manual Programming arbitrary waveforms 1. Restore defaults with this command: *RST 2. Configure the waveform. Examples – The following commands configure a 100kHz arbitrary wave with an amplitude of 25mA, 0mA offset, phase marker off, and 20 second duration: SOUR:WAVE:ARB:DATA -0.5, -0.25, ‘ Define arbitrary data points in 0, 0.3, 0.4 ‘ location 0. SOUR:WAVE:ARB:COPY 1 ‘ Copy points to location 1. SOUR:WAVE:FUNC ARB1 ‘ Select arb wave, location 1.
Model 6220/6221 User’s Manual Wave Functions (6221 Only) 7-15 SCPI commands — wave functions Commands for wave functions are listed in Table 7-4. Table 7-4 Waveform function commands Command Description Default SOURce[1]:WAVE:FUNCtion Selects wave function. = SINusoid, SQUare, RAMP, or ARBitraryX (0-4) SIN SOURce[1]:WAVE:DCYCle Sets duty cycle. = 0 to 100 (%) 50 SOURce[1]:WAVE:AMPLitude Sets amplitude. = 2e-12 to 0.
7-16 Wave Functions (6221 Only) Model 6220/6221 User’s Manual Table 7-4 (cont.) Waveform function commands Command Description Default Arms 6221 for waveform output. SOURce[1]:WAVE:ARM SOURce[1]:WAVE:INITiate Starts waveform output. SOURce[1]:WAVE:ABORt Aborts waveform output. SOURce[1]:WAVE:DURation:TIME Sets waveform time duration. = 100e-9 to 999999.999 (s) or INFinity. INFinity SOURce[1]:WAVE:DURation:CYCLes Sets waveform duration in cycles. = 0.
A Specifications
6220 Programmable Current Source SOURCE SPECIFICATIONS Range (+5% over range) Accuracy (1 Year) 23°C±5°C ±(%rdg. + amps) Programming Resolution Temperature Coefficient/°C 0°-18°C& 28°-50°C Typical Noise (peak-peak) /RMS3,4,5 0.1Hz-10Hz Settling Time1,2 (1% of final value) 2nA 0.4% + 2pA 100fA 0.02% + 200fA 400/80fA 100μs 20nA 0.3% + 10pA 1pA 0.02% + 200fA 4/0.8pA 100μs 200nA 0.3% + 100pA 10pA 0.02% + 2pA 20/4pA 100μs 2μA 0.1% + 1nA 100pA 0.01% + 20pA 200/40pA 100μs 20μA 0.
6220 Programmable Current Source GENERAL SPECIFICATIONS COMMON MODE VOLTAGE: 250V rms, DC to 60Hz. COMMON MODE ISOLATION: >109Ω, <2nF. SOURCE OUTPUT MODES: Fixed DC level, Memory List. REMOTE INTERFACE: IEEE-488 and RS-232C. SCPI (Standard Commands for Programmable Instruments) DDC (command language compatible with Keithley Model 220) PASSWORD PROTECTION: 11 characters. DIGITAL INTERFACE: Handler Interface: Start of test, end of test, 3 category bits, +5V@300mA supply.
6221 AC and DC Current Source SOURCE SPECIFICATIONS Range (+5% over range) Accuracy (1 Year) 23°C±5°C ±(%rdg. + amps) Typical Output Typical Programming Temperature Settling Time1,2 Noise Response Noise (1% of final value) Resolution Coefficient/°C Bandwidth Output 0°-18°C& 28°- (peak-peak) (peak-peak) (BW) into Output /RMS3,4,5 /RMS3,5 50°C Resp. Fast Resp. Slow Short 0.1Hz-10Hz 10Hz-(BW) (Max) (Typical5) 2nA 0.4% + 2pA 100fA 0.02% + 200fA 400/80fA 250/50pA 10kHz 90μs 100μs 20nA 0.
6221 AC and DC Current Source ARBITRARY FUNCTION GENERATOR WAVEFORMS: Sine, Square, Ramp, and 4 User Defined Arbitrary Waveforms. FREQUENCY ACCURACY4: ±100 ppm (1 Year) AMPLITUDE: 2pA to 210mA peak-peak into loads up to 1012Ω. AMPLITUDE ACCURACY (<10kHz): 2 Magnitude: 1% rdg + 0.2% rng Offset: 0.2% rdg + 0.2% rng SINE WAVE CHARACTERISTICS: Frequency Range: 1mHz to 100kHz.2 Amplitude Flatness: Less than 1dB up to 100kHz.4 SQUARE WAVE CHARACTERISTICS: Frequency Range: 1mHz to 100kHz.2 Overshoot: <2.
B SCPI Tables (Abridged) Appendix B tables Calculate command summary, page B-2 Display command summary, page B-2 Format command summary, page B-3 Output command summary, page B-3 Sense command summary, page B-3 Source command summary, page B-4 Status command summary, page B-7 System command summary, page B-8 Trace command summary, page B-9 Trigger command summary, page B-10 Units command summary, page B-10 The SCPI tables in this section are structured as follows: • • • Only the shortform version of the
B-2 SCPI Tables (Abridged) Model 6220/6221 User’s Manual Table B-1 Calculate command summary Command Description CALC CALC commands (math calculations): :FORM Select math format: NONE, MXB (mX+b), or REC (m/X+b) :KMAT Configure math calculations: :MMF Set “m” for mX+b and m/X+b: -9.99999e20 to 9.99999e20 :MBF Set “b” for mX+b and m/X+b calculation: -9.99999e20 to 9.99999e20 :STAT Enable or disable CALC calculation.
Model 6220/6221 User’s Manual SCPI Tables (Abridged) B-3 Table B-3 Format command summary Command FORM [:DATA] :ELEM - :BORD :SREG Description Reading format commands: Specify data format: ASC, SRE, or DRE Specify data elements: READ, TST, UNIT, RNUM, SOUR, COMP, AVOL (or ALL or DEF) Specify byte order: NORM or SWAP. Select format for reading status registers: ASC, HEX, OCT or BIN. Default ASC READ, TST (Note) ASC Note: *RST default is NORM. SYST:PRES default is SWAP.
B-4 SCPI Tables (Abridged) Model 6220/6221 User’s Manual Table B-6 Source command summary Command Description SOUR Current source output commands: :CLE Clearing the current source: [:IMM] Set output to zero and then turn the output off. :CURR Current source: [:AMPL] Set current source output (amps): -105e-3 to 105e-3 :RANG Select a fixed source range: -105e-3 to 105e-3 :AUTO Enable or disable source auto range. :COMP Set voltage compliance (volts): 0.
Model 6220/6221 User’s Manual SCPI Tables (Abridged) B-5 Table B-6 (cont.) Source command summary Command :COMPliance [,, ...] :APP [,, ...
B-6 SCPI Tables (Abridged) Model 6220/6221 User’s Manual Table B-6 (cont.) Source command summary Command Description :WAVE :FUNC :DCYC :AMPL :FREQ :OFFS :PMAR [:LEV] :OLIN :STAT :ARB :DATA [,, ...] :DATA? :APP [,, ...] :POIN? :COPY :RANG :DUR :TIME Wave function operation: Select wave function: SIN, SQU, RAMP or ARBX (X = 0 to 4).
Model 6220/6221 User’s Manual SCPI Tables (Abridged) B-7 Table B-7 Status command summary Command Description STATus Commands status registers: :MEASurement Measurement event registers: [:EVENt]? Read the event register. :ENABle or Program the enable register. :CONDition? Read the condition register. :OPERation Operation event registers: [:EVENt]? Read the event register. :ENABle or Program the enable register. :CONDition? Read the condition register.
B-8 SCPI Tables (Abridged) Model 6220/6221 User’s Manual Table B-8 System command summary Command :SYST :COMM :SEL :GPIB :ADDR :SER :CONT :RTS :PACE :TERM :BAUD :SEND :ENT? :LOC :REM :RWL :ETH :ADDR :MASK :GAT :DHCP :SAVE :KEY :KCL :BEEP :STAT :PRES :POS :ERR? :CLE :TST :RES :RNUM :RES :VERS? Description Communication interfaces: Select interface: SERial, GPIB, or ETHernet.
Model 6220/6221 User’s Manual SCPI Tables (Abridged) B-9 Table B-8 (cont.) System command summary Command :ABO :SNUM? :REV? :DBO :SNUM? :REV? :PASS :ENAB :CDIS [:CEN] :STAT? :NEW Description Default Analog board: Query serial number of analog board. Query revision level of analog board. Digital board: Query serial number of digital board. Query revision level of digital board. Password: Enable or disable the use of password. Disables protected commands.
B-10 SCPI Tables (Abridged) Model 6220/6221 User’s Manual Table B-10 Trigger command summary Command* INIT [:IMM] ABOR ARM :SOUR :SIGN :TIM :DIR :ILIN :OLIN :OUTP TRIG :SOUR :SIGN :DIR :ILIN :OLIN :OUTP Description Default Trigger initiation: Initiate one trigger cycle. OFF Reset trigger system. Arm layer commands: Select event detector: IMM, TIM, BUS, TLIN, BST, PST, NST, or MAN. Bypass ARM control source.
Index Contact information 1-3 Cooling vents 1-9 A D Accessories 1-4 Analog filter 3-5 Applications 3-16 Arbitrary waveforms 7-7 Arming and Starting the Test 5-10 Averaging filter 6-1 Commands 6-5 Filter count 6-2 Filter window 6-4 Moving filter 6-3 Repeating filter 6-3 Setup and control 6-4 Default settings 1-18 Delta 5-2, 5-13 Configuration 5-15 Measurement units 5-15 Operation 5-16 Setup commands 5-19 Triggering sequence 5-10, 5-16 Differential Conductance 5-2, 5-34 Calculations 5-36 Configuration 5-3
K Q Keys Query commands 1-19 Function 1-6 Operation 1-6 Output control 1-7 Range 1-7 Special 1-6 R Read commands Buffer 5-13 Pre-math 5-13 Rear panel summaries 1-8 Response speed (6221) 3-7 Rotary knob 1-7 RS-232 5-6 L Leakage current 2-8 Line power connection 1-11 LO banana jack 2-3 S M Safety symbols and terms 1-3 SCPI programming 1-19 Serial communications 5-5 Settling time 3-7 Shielding 2-10 Noise shield 2-10 Safety shield 2-11 Sink operation 3-3 Source and compliance editing 3-8 Source output co
Specifications are subject to change without notice. All Keithley trademarks and trade names are the property of Keithley Instruments, Inc. All other trademarks and trade names are the property of their respective companies. A G R E A T E R M E A S U R E O F Specifications are subject to change without notice. All Keithley trademarks and trade names are the property of Keithley Instruments, Inc. All other trademarks and trade names are the property of their respective companies.
