Operator’s Manual AP034 Active Differential Probe
AP034 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.........................................................................................
AP034 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.
AP034 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 AP034 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.
AP034 Active Differential Probe Standard Accessories Hard Case ÷10 Plug-on Attenuator ÷20 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, ÷10, ÷20 Input Coupling: DC. AC Coupling obtained by installing AC Coupling Adapter.
AP034 Active Differential Probe probe tip depends on proximity to probe cable ground, and is therefore non-reproducible. Teledyne LeCroy has chosen to use a reproducible method of measurement, rather than obtain a more optimistic measurement. Typical Electrical Characteristics Typical characteristics are parameters with no guaranteed performance. Tests for typical characteristics are not provided in the Performance Verification Procedure.
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.
AP034 Active Differential Probe Operation CAUTION: The input circuits in the AP034 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 AP034, you are advised to take precautions against potential instrument damage due to ESD.
Operator’s Manual 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. Therefore, it is desirable to use the same length and type of wire and connectors for both input connections.
AP034 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 AP034 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 NOTE The AP034 Active Differential Probe transmits the measured signal differentially through the probe cable. This essentially eliminates signal degradation from ground loop effects within the probe. However, creating a ground loop may introduce signal distortions in the test circuit itself, or in any coaxial cable between the ADPPS power supply and the test instrument. Selecting the Proper Range The AP034 Active Differential Probe has a fixed gain of X1 (unity).
AP034 Active Differential Probe When using a differential probe or amplifier, be careful to avoid exceeding the common mode range. Because the common mode signal is rejected by the differential probe, and is not displayed, changes in the amplitude of the common mode component are not apparent to the user. Exceeding the common mode range may introduce distortion into the AP034 output.
Operator’s Manual The AP034 offset allows you to measure signals up to 2.0 V (1.6 V of offset plus 400 mV of output signal). With accessory plug-on attenuators, the effective offset is increased, and input signal 0f 20V (÷10) or 40 V (÷20) may be view ed. The peak signal that can be viewed at any equivalent scale factor is the Input Differential Mode Range plus the offset used. See Adding Offset on the following page.
AP034 Active Differential Probe Adding Offset When the AP034 Active Differential Probe is used with a Teledyne LeCroy oscilloscope equipped with ProBus interface, the probe offset can be controlled with the channel OFFSET knob. The buttons on the probe housing will be disabled. When used with the ADPPS Power Supply on instruments that lack ProBus support, offset can be controlled with the buttons on the probe’s front panel.
Operator’s Manual NOTE: Probe offset is controlled with the channel OFFSET knob in oscilloscope firmware versions 8.1.0 or higher (including X-Stream firmware). The current offset value is displayed above the graticule for a few seconds after a change is made by turning the knob. In prior software versions, the channel OFFSET knob adjusted the offset of the oscilloscope input rather than the probe offset.
AP034 Active Differential Probe Figure 5, Layout Dimensions for Test Fixtures 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.
Operator’s Manual service facility for diagnosis and exchange. A defective probe under warranty will be replaced with a factory refurbished probe. A probe that is not under warranty can be exchanged for a factory refurbished probe. A modest fee is charged for this service. The defective probe must be returned in order to receive credit for the probe core. Troubleshooting If the probe is not operating properly the problem may be the way in which it is used.
AP034 Active Differential Probe 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.
Operator’s Manual 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).
AP034 Active Differential Probe 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.
Operator’s Manual Table 3, Replaceable Part Numbers Teledyne LeCroy Part Number Reference Description Rev Qty. 1 529-304-001 Plastic probe tip housing Top A 1 2 377-000-007 Teledyne LeCroy AP034 Probe Tip Label A 1 3 529-304-003 Plastic probe tip housing End A 1 4 529-304-002 Plastic probe tip housing Bottom A 1 5 555-001-000 #2 Allen Screw, Black A 1 6 554-425-003 Screw, M 2.
AP034 Active Differential Probe Matching Procedure for ÷10 Plugs The ÷10 and ÷20 Plug-on attenuators provided as standard accessories with the AP034 are calibrated to match the specific probe they are 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 AP034 to the test oscilloscope. If the test oscilloscope is not equipped with ProBus, use the ADPPS to provide power for the AP034. 2. Attach the ÷or ÷Attenuator Adapter to the AP034 probe tip. 3. Insert 0.025 in. (0.
AP034 Active Differential Probe 11. Using the square adjustment tool, adjust the +LF Comp (See Figure 7) 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 7, ÷10 Attenuator Adjustment Locations 12.
Operator’s Manual Performance Verification This procedure can be used to verify the warranted characteristics of the AP034 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.
AP034 Active Differential Probe Table 4, Performance Verification Test Equipment Description Wide Band Oscilloscope 1 Minimum Requirements Test Equipment Examples Minimum 1 GHz bandwidth Teledyne LeCroy LC584A 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 AP034 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 AP034 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.
AP034 Active Differential Probe 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. Set the mode of the Function Generator to Sine Wave; the frequency to approximately 1 kHz; and the output amplitude to approximately 200 mV rms, as measured by the DMM. 7.
Operator’s Manual B. Check High Frequency Common Mode Rejection Ratio (CMRR) NOTE: Common Mode Rejection Ratio (CMRR) is defined as the Differential Mode Gain divided by the Common Mode Gain (normalized inverse of the Common Mode response). At frequencies below approximately 250 MHz, the bandwidth related attenuation in the AP034 Active Differential Probe is so insignificant that the Differential Mode Gain can be assumed to be unity (1.0). 1.
AP034 Active Differential Probe 10. Move the high frequency sine wave generator output cable from the oscilloscope channel 2 input to the Common Mode Drive 50 ohm Termination connector of the AP033/AP034 Calibration Fixture. 11. Set the high-frequency sine wave generator RF Output to ON. 12. Set the oscilloscope to display channel 1 only, set the trigger source to channel 1, and set the channel 1 vertical scale factor as needed to measure the amplitude of the displayed waveform.
Operator’s Manual second BNC cable from the remaining end of the BNC Tee adapter to the Common Mode Drive No Termination input connector of the AP033/AP034 Calibration Fixture. CAUTION: Make sure that the Common Mode Drive No Termination connection is used. Prolonged application of the power levels used in the low frequency common mode test may damage the termination resistance in either 50 ohm Termination input of the AP033/AP034 calibration fixture. 4.
AP034 Active Differential Probe 15. Calculate the “Common Mode Rejection Ratio (CMRR) at 1 MHz” by dividing 8000 mV by the measured Common Mode Signal recorded in step C-14. Record the result in the Test Record. 16. Verify that the Common Mode Rejection Ratio at 1 MHz is greater than 100:1 (40 dB). 17. Remove all cables and test fixtures from the AP034 probe. This completes the Performance Verification of the AP034.
Operator’s Manual Model: Serial Number: AP034 Asset or Tracking Number: Date: Technician: MODEL SERIAL NUMBER CALIBRATION DUE DATE OSCILLOSCOPE DIGITAL MULTIMETER LEVELED SINE WAVE GENERATOR HF SINE WAVE GENERATOR FUNCTION GENERATOR 1 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.
AP034 Active Differential Probe Adjustment Procedure Introduction You can use this procedure to adjust the AP034 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 AP034 Active Differential Probe every year.
Operator’s Manual 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.
AP034 Active Differential Probe Description Minimum Requirements Example Test Equipment 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.
Operator’s Manual 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.
AP034 Active Differential Probe Procedure A. Adjust Coarse DC Balance (R226) 1. If necessary, set the probe offset to 0.000 V by rotating the OFFSET knob in the CHANNEL section of the oscilloscope. 2. Insert the two-pin shorting plug into the socket on the Logic Board. Use the two holes closest to the probe cable (Figure 9). Figure 8, AP033 Logic Board 3. To enter the Cal Mode, push either of the two offset buttons that protrude through holes in the Logic Board. 4.
Operator’s Manual B. Adjust Fine DC Balance (R304) 1. Remove the shorting plug from the Logic Board. 2. Reinsert the shorting plug into the two holes near the end of the Logic Board. (Figure 8.) 3. Reenter Cal Mode by pushing either of the two buttons that protrude through holes in the Logic Board. 4. ,Remove the BNC cable from the precision 50 Ω terminator connected to the DMM. 5. Short the output BNC connector by reconnecting the cable to the SHORT connector on the AP033/AP034 Calibration Fixture.
AP034 Active Differential Probe C. Adjust Low Frequency CMRR (R7) 1. Leave the BNC cable connected to the probe end of the ProBus extension cable. Connect a 50Ω BNC Through Terminator on the other end of the BNC cable. Connect the male end of the 50Ω terminator to channel 3 on the scope. The scope end of the ProBus extension cable should remain connected to channel 1 of the scope, although there is no signal cable connected. 2.
Operator’s Manual 10. Set the oscilloscope to display channel 3. The waveform is the common mode signal. Turn the offset as necessary to keep the trace on screen. Turn on Math Channel A. Press MATH SETUP, then REDEFINE A. Set the A Math type to Average, Avg Type to Continuous, with 1:15 weighting, of channel 3. Turn off the trace 3 display. Use the Math Zoom and Position controls as necessary to view the waveform. 11. Adjust LF CMRR (R7) for minimum amplitude. (See Figure 11 for location.) Figure 11,.
AP034 Active Differential Probe 5. Connect the other end of the cable to the DMM input, making sure that the plug corresponding to the BNC shield (marked “Ground”) is connected to the LO or COM input. 6. Set the DC Voltage Source to read as close as possible to +1.600 V on the DMM. 7. Autobalance the AP034 by pressing the AUTOBALANCE menu button located in the “COUPLING” menu twice, or by pressing and holding both probe offset buttons for at least two seconds. 8.
Operator’s Manual 21. The trace should be offset from the center line by the same amplitude but opposite polarity of the value noted in step E-16. 22. Repeat steps E-13 through E-21 as necessary until the errors at +1.6 V and at –1.6 V are approximately equal, and both are within 10 mV of the center scale. Reverse the polarity of the dual banana plug adapter at the output of the DC voltage source, and the corresponding probe offset value with each repetition. 23.
AP034 Active Differential Probe F. Adjust Final Attenuator Compensation (C17) NOTE: The calibrator signal from a Teledyne LeCroy oscilloscope is the recommended signal source for this adjustment. If another oscilloscope is being used for this procedure, make sure that the square wave source has adequate flatness (minimum overshoot and undershoot.) 1. Press the UTILITIES button, then select the CAL BNC Setup menu.
Operator’s Manual 3. Set the oscilloscope display to channel 4, coupling to DC1MΩ , vertical scale factor to 200 mV/div, and the trigger source to channel 4. Adjust the oscilloscope trigger level as necessary for a stable display. 4. Set the oscilloscope to display channel 1, and vertical scale factor to 10 mV/div. Set the OFFSET to 0.0 mv 5. 5. Adjust Attenuator CMRR (capacitor C18A) for minimum amplitude shift of the displayed waveform at the trigger point in time. See Figure 9 for adjustment location. 6.
AP034 Active Differential Probe I. Attenuator Matching and Final Check 1. Repeat the Performance Verification procedure to ensure compliance with the warranted specifications. 2. Perform the Attenuator Matching Procedure listed on page 5-8. Apply calibration seals in accordance with your quality procedures. This concludes the Adjustment Procedure. Repeat the Performance Verification procedure to complete the calibration of the AP034. This concludes the Adjustment Procedure.
Operator’s Manual 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.
AP034 Active Differential Probe 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.
Operator’s Manual 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.
AP034 Active Differential Probe 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.
Operator’s Manual 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.
AP034 Active Differential Probe 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.
