Operator’s Manual AP033 Active Differential Probe
AP033 Active Differential Probe Operator’s Manual May 2013
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Operator’s Manual Table of Contents Safety Instructions............................................................................................... 1 Symbols .................................................................................................................. 1 Precautions............................................................................................................. 1 Operating Environment.........................................................................................
AP033 Active Differential Probe Matching Procedure for ÷10 Plugs ...................................................................... 22 Equipment Required.............................................................................................22 Procedure .............................................................................................................23 Performance Verification ................................................................................... 25 Test Equipment Required .
Operator’s Manual Safety Instructions This section contains instructions that must be observed to keep this oscilloscope accessory operating in a correct and safe condition. You are required to follow generally accepted safety procedures in addition to the precautions specified in this section. The overall safety of any system incorporating this accessory is the responsibility of the assembler of the system.
AP033 Active Differential Probe Do not overload. To avoid electric shock, do not apply any potential that exceeds the maximum rating of the probe and/or the probe accessory, whichever is less. Observe all terminal ratings of the instrument before connecting the probe. Be careful not to damage the insulation surface when making measurements. Use only within operational environment listed. Do not use in wet or explosive atmospheres. Keep product surfaces clean and dry. Use indoors only. Handle with care.
Operator’s Manual Overview Description The AP033 is a wide band differential active probe. The probe features low noise, low input capacitance, high common mode rejection, and FET-buffered inputs in the probe head. User selectable attenuation and offset give the probe flexibility to measure a large range of signal amplitudes. Plug-on attenuator and AC coupling accessories further extend the application range.
AP033 Active Differential Probe Standard Accessories Hard Case ÷10 Plug-on Attenuator Plug-on AC Coupler Probe Connection Accessory Kit: Flex Lead Set (1) Mini Clip, 0.8 mm (3) Mini Clip, 0.
Operator’s Manual Specifications Nominal Characteristics Nominal characteristics describe parameters and attributes that have are guaranteed by design, but do not have associated tolerances. Input Configuration: True Differential (+ and – Inputs); with shield Ground connector. Effective Gain1: X1, X10, ÷10, ÷1002 Input coupling: DC. AC Coupling obtained by installing AC Coupling Adapter.
AP033 Active Differential Probe 4 Teledyne LeCroy measures CMRR with a fixture that connects the probe tip ground to the signal source ground. This method is necessary to obtain a reproducible CMRR measurement. Often, users leave the probe tip ungrounded when measuring high frequency signals. Not grounding the probe tip can actually improve CMRR by allowing some of the common mode signal to be impressed across the entire length of the probe cable instead of from probe tip to probe ground.
Operator’s Manual Figure 1, Typical CMRR Graphs Temperature: Input Connectors: Power Requirements: Control Housing: Compatible with 0.025” (0.635 mm) square pins. 0.036” (0.91 mm) maximum diameter (for round pins) Powered from oscilloscope through ProBus interface or with ADPPS power supply. Dimensions Length: 3.625 in (9.2 cm) Width: 1.50 in (3.8 cm) Height: 1.00 in (2.5 cm) Head: Length: 4.0 in (10.1 cm) w/o Attenuator or AC Coupler Width: 2.25 in (2.25 cm) Height: 0.625 in (1.
AP033 Active Differential Probe Operation CAUTION: The input circuits in the AP033 incorporate components that protect the probe from damage resulting from electrostatic discharge (ESD). Keep in mind that this is an active probe, and it should be handled carefully to avoid damage. When using the AP033, you are advised to take precautions against potential instrument damage due to ESD.
Operator’s Manual can greatly reduce this effect by using short interconnection leads, and twisting them together to minimize the loop area. High common mode rejection requires precise matching of the relative gain or attenuation in the + and – input signal paths. Mismatches in additional parasitic capacitance, inductance, delay, and a source impedance difference between the + and – signal paths will lower the common mode rejection ratio.
AP033 Active Differential Probe Probe Input Loading Attaching any probe to a test circuit will add some loading. In most applications, the high impedance of the AP033 Active Differential Probe inputs imparts an insignificant load to the test circuit. However at very high frequencies, the capacitive reactance of the probe’s input capacitance may load the circuit enough to affect measurement accuracy.
Operator’s Manual The best recommendation for connecting or not connecting the probe ground is to try both configurations and select the one that performs the best. NOTE The AP033 Active Differential Probe transmits the measured signal differentially through the probe cable. This essentially eliminates signal degradation from ground loop effects within the probe.
AP033 Active Differential Probe Table 1, AP033 Dynamic ranges and input capacitance at different attenuator settings ÷1 Attenuation ÷10 Attenuation ÷100 Attenuation •±4.2 V •±42 V • ±42 V •±400 mV • ±4 V • ±40 V •±40 mV • ±400 mV • ±4 V Input Capacitance, each side to Ground 6.0 pF 3.0 pF 1.9 pF Input Capacitance each side to Ground with AC Coupler 7.3 pF 4.3 pF 3.
Operator’s Manual With oscilloscope software versions 7.6.0 and higher, the probe gain, internal attenuation, and offset can be conveniently controlled through the oscilloscope’s user interface. The common mode range is also displayed. Manual control through the oscilloscope user interface can be found in the COUPLING menu or the Channel dialog of the channel to which the probe is connected.
AP033 Active Differential Probe Table 2, Recommended oscilloscope settings to obtain desired equivalent Volts/Division Equivalent Scale Factor Oscilloscope Scale Factor AP033 Attenuation AP033 Gain Common Mode Range Differential Mode Range Maximum Offset Input Noise (nV/√Hz) 100 μV/Div 1 mV/Div ÷1 X10 • ±4.2 V • ±40 mV • ±400 mV 6 200 μV/Div 2 mV/Div ÷1 X10 • ±4.2 V • ±40 mV • ±400 mV 6 500 μV/Div 5 mV/Div ÷1 X10 • ±4.
Operator’s Manual Figure 4, Effect of Differential Offset When the AP033 is used with a Teledyne LeCroy oscilloscope equipped with a ProBus interface and software versions 7.6.0 to 8.0.0, the probe offset must be controlled through either the Probe Offset menu selection in the COUPLING screen, or the buttons on the probe body. The channel OFFSET control does not change the probe offset and, therefore, should not be used.
AP033 Active Differential Probe Upon successful completion of the Autobalance cycle, all four of the EFFECTIVE GAIN indicators will be briefly illuminated. If an input signal is present during auto balancing and the routine fails, the EFFECTIVE GAIN indicators will not illuminate. The probe will then revert to the offset values that resulted from the last successful completion of the Autobalance cycle. In many situations, this will be adequate to make routine measurements.
Operator’s Manual Maintenance This probe is a high quality, precision instrument. To maintain accuracy and signal fidelity, mechanical shock should be avoided, as well as damage to the cable through excessive bending. To achieve the small 2.5 mm tip size, the input tip diameter is narrower than those in larger probes. Avoid placing excessive force sideways on the tip. Should the tip become damaged, it may be replaced. Other maintenance and component replacement should be referred to qualified personnel.
AP033 Active Differential Probe Troubleshooting If the probe is not operating properly the problem may be the way in which it is used. Before assuming the probe is defective, perform the following troubleshooting procedures. A. Trace Off Scale This is typically caused by improper offset setting, or by an input signal that exceeds the probe differential or common mode range. 1. Remove the input signal from the probe, return the offset to zero, and Autobalance the probe.
Operator’s Manual B. Incorrect Frequency Response Possible causes are a defective probe or oscilloscope, poor connections, or poor grounding. 1. Verify that the BW limiting of the oscilloscope is off. 2. Connect the probe to another oscilloscope. If the probe now measures properly, the problem may be in the oscilloscope. 3. If the probe behaves as if it is ac-coupled at high frequency, check for an open input connection. 4.
AP033 Active Differential Probe Returning a Probe Return a probe for calibration or service by contacting your local Teledyne LeCroy sales representative. They tell you where to return the product. All returned products should be identified by both model and serial number. Provide your name and contact number, and a description of the defect or failure (if possible).
Operator’s Manual 8. If returning a probe to a different country, also: Mark shipments returned for service as a “Return of US manufactured goods for warranty repair/recalibration.” If there is a cost involved in the service, put the service cost in the value column and the replacement value of the probe in the body of the invoice marked “For insurance purposes only.” Be very specific as to the reason for shipment. Duties may have to be paid on the value of the service.
AP033 Active Differential Probe Matching Procedure for ÷10 Plugs The ÷10 Plug-on attenuator provided as a standard accessory with the AP033 is calibrated to match the specific probe it was shipped with. Individual probes will have small variations in parasitic capacitance within the input circuits. To obtain maximum common mode rejection performance, the attenuators are calibrated to match a specific probe during the manufacturing process.
Operator’s Manual Note: You can fabricate the Adjustment Tool by flattening the end of a 0.025 in. (0.635 mm) square pin with a file. Insert the pin into a short length of rigid plastic tubing to serve as a handle. Procedure 1. Attach the AP033 to the test oscilloscope. If the test oscilloscope is not equipped with ProBus, use the ADPPS to provide power for the AP033. 2. Attach the ÷Attenuator Adapter to the AP033 probe tip. 3. Insert 0.025 in. (0.
AP033 Active Differential Probe 11. Using the square adjustment tool, adjust the +LF Comp (See Figure 6) to achieve the best square corner and flat top of the displayed waveform. Note that the added capacitance of the adjustment tool may change the compensation of the waveform when it is inserted. The correct adjustment is achieved when the best corner is displayed with the adjustment tool removed . Figure 6, ÷10 Attenuator Adjustment Locations 12.
Operator’s Manual Performance Verification This procedure can be used to verify the warranted characteristics of the AP033 Active Differential Probe. You can do the performance verification without removing the instrument covers and exposing yourself to hazardous voltages. Adjustment should only be attempted if a parameter measured in the Performance Verification Procedure is outside of the specified limits. Adjustment should only be performed by qualified personnel.
AP033 Active Differential Probe Table 3, Performance Verification Test Equipment Description Minimum Requirements Example Test Equipment Wide Band Oscilloscope (see note) Minimum 1 GHz bandwidth Teledyne LeCroy Wavepro 950 2 mV to 5 V scale factors ProBus interface equipped 2% vertical accuracy Digital Multimeter Function Generator DC: 0.1% accuracy Agilent Technologies 34401A AC: 0.
Operator’s Manual Preliminary Procedure 1. Connect the AP033 Active Differential Probe to the female end of the ProBus Extension Cable. Connect the male end of the ProBus extension cable to Channel 1 of the oscilloscope. 2. Turn the oscilloscope on and allow at least a 30- minutes warm-up time for the AP033 and test equipment before performing the Verification Procedure. 3. Turn on the other test equipment and allow these to warm up for the time recommended by the manufacturer. 4.
AP033 Active Differential Probe 3. Using a BNC female-to-female adapter, connect one end of a BNC cable to the probe end of the ProBus Extension Cable. Connect the Precision 50Ω Terminator to the other end of the BNC cable. 4. Connect one end of a second BNC cable to the output of the Function Generator. Attach the BNC-to-dual-male banana plug adapter to the free end of the second BNC cable. Connect the banana plugs to the Digital Multimeter (DMM). 5. Set the DMM to measure AC Volts. 6.
Operator’s Manual 18. After the DMM reading has stabilized, record the measured output amplitude to 100 μV resolution in the Test Record. 19. Divide the measured output voltage recorded in step A-18 by the sine wave generator output voltage (probe input voltage) from step A-7. Subtract 1.0 from the ratio and multiply the result by 100 to get the error in percent. 20. Record the answer to two significant places (±x.xx%) on line A-20 in the Test Record. 21. Verify that the X10 gain error is less than ±2%.
AP033 Active Differential Probe 2. Carefully move the AP033 probe head from the Differential Drive No Termination connector of the AP033/AP034 Calibration Fixture to the Differential Drive 50 Ohm Termination connector. Make sure that the probe is fully engaged in the fixture. 3. Set the oscilloscope to display channel 1.Set Coupling to DC 1 MΩ, and Global BWL to Off. Autobalance the AP033 by pressing the AUTOBALANCE button twice. Set the oscilloscope trigger mode to AUTO. 4.
Operator’s Manual 14. Carefully move the AP033 probe head from the Differential Drive 50 Ohm Termination connector of the AP033/AP034 Calibration Fixture to the Common Mode Drive 50 Ohm Termination connector. Make sure the probe is fully engaged in the fixture. 15. Set the oscilloscope to display channel 2, channel 2 vertical scale to 0.5 Volt/div, channel 2 input coupling to DC50Ω, and trigger source to channel 2. If necessary, adjust the trigger level for a stable display. 16.
AP033 Active Differential Probe C. Check Low Frequency CMRR NOTE: The attenuation of the AP033 Active Differential Probe below 10 MHz is so insignificant that the Differential Mode Gain can be assumed to be unity (1.0). Because greater amplitudes are required to measure the higher CMRR specifications at low frequencies, the Function Generator will be used in place of the leveled sine wave generator for the low frequency CMRR test. 1.
Operator’s Manual 9. Calculate the Common Mode Rejection Ratio (CMRR) at 70 Hz by dividing 8,000 mV by the measured Common Mode Signal recorded in step C-8 (direct reciprocal of the Common Mode Gain). Record the result to two-digit resolution (xx,000 : 1) in the Test Record. 10. Verify that the Common Mode Rejection Ratio at 70 Hz is greater than 3,160:1 (70 dB). 11. Set the oscilloscope to display channel 2. Change the horizontal scale factor to 0.5 s/division. Set the BWL on channels 1 and 2 to 200 MHz.
AP033 Active Differential Probe Model: Serial Number: AP033 Asset or Tracking Number: Date: Technician: MODEL SERIAL NUMBER CALIBRATION DUE DATE OSCILLOSCOPE DIGITAL MULTIMETER LEVELED SINE WAVE GENERATOR HF SINE WAVE GENERATOR 1 FUNCTION GENERATOR N/A 1 The function generator provides stimulus for making relative measurements. The output amplitude of the generator is measured with the DMM or oscilloscope in the procedure. Thus, the generator is not required to be calibrated.
Operator’s Manual Adjustment Procedure Introduction You can use this procedure to adjust the AP033 Active Differential Probe to meet the warranted specifications. This procedure should only be performed if the instrument fails the Performance Verification tests. If the probe cannot be adjusted to meet the Performance Verification limits, repair may be necessary. To ensure instrument accuracy, check the calibration of the AP033 Active Differential Probe every year.
AP033 Active Differential Probe Test Equipment Required The table on the next page lists the test equipment and accessories, or their equivalents, that are required for complete calibration. Specifications given for the test equipment are the minimum necessary for accurate calibration. All test equipment is assumed to be correctly calibrated and operating within the specifications listed. Detailed operating instructions for the test equipment are not given in this procedure.
Operator’s Manual Description Minimum Requirements Example Test Equipment settable to 1 mV resolution Termination, precision 50 Ω ± 0.05% Teledyne LeCroy TERM-CF01 Termination, BNC 50 Ω through male-female Pomona 4119-50 Calibration Fixture ProBus Extension Cable Teledyne LeCroy PROBUS-CF01 Calibration Fixture AP033/AP034 Calibration Fixture Teledyne LeCroy AP03X-CF01 BNC coaxial cable (2 Required) male-male BNC, approx.
AP033 Active Differential Probe Preliminary Procedure 1. Using pliers, carefully remove each of the push buttons from the ProBus interface housing by gently pulling them away from the housing. 2. Remove the two screws that secure the plastic cover on the cable end of the ProBus interface housing. Gently pull on the probe cable to slide the circuit board assembly from the metal housing. 3. Remove the 5/64 in. (2 mm) Allen head cap screw from the small cover on the back of the probe tip.
Operator’s Manual Procedure A. Adjust Preliminary Probe DC Balance (R36) 1. From the oscilloscope’s front panel, select channel 1. Set the AP033 Atten/Gain to Manual, the Probe Atten to /10, and the Probe Gain to X10. 2. If necessary, set the probe offset to 0.000 V. 3. Connect one end of a BNC cable to the probe end of the ProBus Extension Cable. Attach the precision 50 Ω terminator to the opposite end of the BNC cable. 4.
AP033 Active Differential Probe Figure 8, Probe Tip Adjustment Locations B. Adjust Coarse DC Balance (R226) 1. Remove the shorting plug from the Logic Board. 2. Change the channel 1 Probe Gain to X1. 3. Reinsert the shorting plug into the two holes near the end of the Logic Board. 4. Reenter Cal Mode by pushing any one of the four buttons that protrude through holes in the Logic board. 5. Adjust Coarse DC Bal (R226) on the amplifier board for Figure 9 for location.
Operator’s Manual C. Adjust Fine DC Balance (R304) 1. Remove the shorting plug from the Logic Board. 2. In the Channel 1 “COUPLING” menu, change the Probe Gain to X10. 3. Reinsert the shorting plug into the two holes near the end of the Logic Board. (Figure 6.) 4. Reenter Cal Mode by pushing any one of the four buttons that protrude through holes in the Logic board. 5. Remove the BNC cable from the precision 50 Ω terminator attached to the DMM. 6.
AP033 Active Differential Probe D. Adjust ÷10 Attenuator CMRR (R7) 1. Keep the BNC cable attached to the probe end of the ProBus extension cable. Attach a 50Ω BNC Through Terminator on the other end of the BNC cable. Attach the male end of the 50Ω terminator to channel 3 on the oscilloscope. The oscilloscope end of the ProBus extension cable should remain connected to channel 1 of the oscilloscope although there is no signal cable attached. 2.
Operator’s Manual weighting, of channel 3. Turn off the trace 3 display. Use the Math Zoom and Position controls as necessary to view the waveform. 12. Adjust ÷ 13. Remove the BNC cable from the output of the Function Generator and the calibration fixture. Leave the BNC cable from the SYNC output to the oscilloscope external trigger input in place. Remove the BNC cable and 50Ω terminator from channel 3. E. Adjust OFFSET (R330) 1.
AP033 Active Differential Probe 13. In the CHANNEL section of the oscilloscope, set the probe offset to +0.4000 V by rotating the OFFSET knob (or with the OFFSET knob linked to the COUPLING menu when using the older software.) 14. Allow 10 seconds for the AP033 to stabilize. 15. Note the amplitude of the trace from center screen. 16. Adjust Offset Cal (R330) to position the trace to approximately ½ the amplitude from center screen noted in the previous step.
Operator’s Manual 6. Record the DMM reading. Be careful not to alter the output amplitude of the generator after the measured value has been recorded. 7. Remove the banana plug adapter and connect the free end of the cable to the Differential Drive no Termination connector on the calibration fixture. 8. Connect the AP033 Output cable with 50 Ω precision termination to the DMM. 9. Adjust GAIN (R322C) so that the DMM reading is within ±1 mV (0.5%) of the reading recorded in step F-6. (See Figure 11.) 10.
AP033 Active Differential Probe H. Adjust Final Attenuator CMRR (C18A) 1. Carefully move the AP033 probe head from the Differential Drive 50 Ohm Termination portion of the AP033/AP034 Calibration Fixture to the Common Mode Drive 50 Ohm Termination portion. 2. Remove the BNC cable from the Differential Drive 50 Ohm Termination connector of the AP033/AP034 Calibration Fixture. Connect one end of the BNC cable to the Common Mode Drive 50 Ohm Termination connector of the AP033/AP034 Calibration fixture.
Operator’s Manual the boards into the housing being careful to align the screw holes in the end cover with the corresponding channels in the corners of the housing. 7. Insert and tighten the two screws which secure the end panel to the ProBus interface housing. Avoid over tightening the screws as the cover may warp. 8. Replace the four push button caps, pressing each fully to seat the cap on the button shaft. J. Attenuator Matching and Final Check 1.
AP033 Active Differential Probe Reference Information Differential Mode and Common Mode Differential probes amplify the voltage difference that appears between the + and – inputs. This voltage is referred to as the Differential Mode or Normal Mode voltage. The voltage component that is referenced to earth ground, and is identical on both inputs, is rejected by the amplifier. This voltage is referred to as the Common Mode voltage, because it is common to both inputs.
Operator’s Manual Common Mode Rejection Ratio The ideal differential probe or differential amplifier would amplify only the differential mode voltage component and reject all of the common mode voltage component. Real differential probes and amplifiers are less than ideal, so a small portion of the common mode voltage component appears in the output. Common Mode Rejection Ratio (CMRR) is the measure of how effectively the probe or amplifier rejects the common mode voltage component.
AP033 Active Differential Probe Certifications This section certifies the probe’s Electromagnetic Compatibility (EMC), Safety and Environmental compliance. EMC Compliance EC DECLARATION OF CONFORMITY - EMC The probe meets intent of EC Directive 2004/108/EC for Electromagnetic Compatibility.
Operator’s Manual AUSTRALIA & NEW ZEALAND DECLARATION OF CONFORMITY—EMC The probe complies with the EMC provision of the Radio Communications Act per the following standards, in accordance with requirements imposed by Australian Communication and Media Authority (ACMA): CISPR 11:2003 Radiated and Conducted Emissions, Group 1, Class A, in accordance with EN613261:2006 and EN61326-2-1:2006. Australia / New Zealand Contacts: Vicom Australia Ltd.
AP033 Active Differential Probe Environmental Compliance END-OF-LIFE HANDLING The probe is marked with this symbol to indicate that it complies with the applicable European Union requirements to Directives 2002/96/EC and 2006/66/EC on Waste Electrical and Electronic Equipment (WEEE) and Batteries. The probe is subject to disposal and recycling regulations that vary by country and region. Many countries prohibit the disposal of waste electronic equipment in standard waste receptacles.
Operator’s Manual Contact Teledyne LeCroy Teledyne LeCroy Service Centers United States and Canada World Wide Corporate Office Teledyne LeCroy Corporation 700 Chestnut Ridge Road Chestnut Ridge, NY, 10977-6499, USA Ph: 800-553-2769 / 845-425-2000 FAX: 845-578-5985 teledynelecroy.com Support: contact.corp@teledynelecroy.com Sales: customersupport@teledynelecroy.
AP033 Active Differential Probe 54 922260-00 Rev A
