Teledyne-lecroy DA1855A User Manual

Operator’s Manual DA1855A Differential Amplifier

DA1855A Differential Amplifier 4 922258-00 Rev A Specifications These specifications are valid for instruments when the following conditions have bee

Operator’s Manual 922258-00 Rev A 5 General, continued Auto Zero Amplifier initiates an automatic balance cycle, when either gain button is depresse

DA1855A Differential Amplifier 6 922258-00 Rev A Precision Voltage Generator Output Range ± 15.5 V Output Impedance ≈ 10 Ω Resolution 100 μV Contr

Operator’s Manual 922258-00 Rev A 7 Typical Characteristics Typical characteristics describe parameters, which do not have guaranteed performance. Te

DA1855A Differential Amplifier 8 922258-00 Rev A Physical Characteristics Height DA1855A 7.29 cm (2.87 inch) DA1855A-PR2 8.75 cm (3.4 inch) Width DA

Operator’s Manual 922258-00 Rev A 9 Overview The DA1855A is a stand-alone high performance 100 MHz differential amplifier. It is intended to act as s

DA1855A Differential Amplifier 10 922258-00 Rev A Model Description The DA1855A series is comprised of 2 models which differ in physical configurati

Operator’s Manual 922258-00 Rev A 11 Optional Accessories • Service Manual, containing adjustments, repair and replacement part information P/N: DA

DA1855A Differential Amplifier 12 922258-00 Rev A Front Panel Input Connectors Signals applied to the +INPUT and the –INPUT are connected either dir

Operator’s Manual 922258-00 Rev A 13 Unbalanced source impedances can have an adverse effect on common mode rejection. For example, a differential so

DA1855A Differential Amplifier 14 922258-00 Rev A –3 dB point is 0.016 Hz. This extremely low frequency cut off is useful for observing low frequency

Operator’s Manual 922258-00 Rev A 15 PVG to null out an input voltage up to ± 155.00 Volt which is ten times larger than the actual PVG voltage. The

DA1855A Differential Amplifier 16 922258-00 Rev A Differential Offset VDIFF (differential offset voltage) is an instrument mode rather than a type o

Operator’s Manual 922258-00 Rev A 17 50 Ω load. Without the load, the filter's frequency response and transient response are altered. 1 MHz The

DA1855A Differential Amplifier 18 922258-00 Rev A Precision Voltage Generator Offset Voltage The rear panel OFFSET VOLTAGE BNC (PVG) output connector

Operator’s Manual 922258-00 Rev A 19 Table 2 and Table 3 will help the operator stay within the maximum input voltage limits and understand the relat

DA1855A Differential Amplifier 20 922258-00 Rev A Remote Operation A REMOTE connector on the rear panel of the DA1855A allows total control of the i

Operator’s Manual 922258-00 Rev A 21 When used without ProBus interface, the instrument can be set to factory default settings by pressing the VCOMP

DA1855A Differential Amplifier 22 922258-00 Rev A More sensitive settings (e.g. 100µV/div) available on some oscilloscopes can be used, but their use

Operator’s Manual 922258-00 Rev A 23 compensation procedure can result in a significant decrease in the CMRR capability of any differential probe pai

DA1855A Differential Amplifier Operator’s Manual February 2013

DA1855A Differential Amplifier 24 922258-00 Rev A Power Connection Check to make sure the power switch located on the rear panel is in the OFF positi

Operator’s Manual 922258-00 Rev A 25 Figure 2, Block Diagram VDIFF Mode. Setting Up the Oscilloscope with ProBus Interface Connect the RJ-45 type co

DA1855A Differential Amplifier 26 922258-00 Rev A Make these settings: PVG Mode OFF +Coupling DC –Coupling Grounded (OFF) DA1855A (Atten/Gain) Au

Operator’s Manual 922258-00 Rev A 27 Comparison Voltage Operation (VCOMP) Set the DA1855A as follows: PVG Mode OFF +Coupling DC –Coupling Grounded

DA1855A Differential Amplifier 28 922258-00 Rev A the centerline. Following are a few observations on using the DA1855A comparison voltage mode (VCOM

Operator’s Manual 922258-00 Rev A 29 Set the Function generator’s output to 50 kHz and 100 mVp-p sine wave and the output connected to the DA1855’s +

DA1855A Differential Amplifier 30 922258-00 Rev A Following are a few observations on using the differential offset mode (VDIFF) of the DA1855A: • B

Operator’s Manual 922258-00 Rev A 31 Attenuator and Gain Operation Connect the function generator output to the +INPUT BNC connector and apply a sine

DA1855A Differential Amplifier 32 922258-00 Rev A Press the –INPUT’s VCOMP button. This internally applies the Precision Voltage Generator’s output t

Operator’s Manual 922258-00 Rev A 33 • By using the DA1855A in the comparison voltage mode and the oscilloscope in a high sensitivity setting, highl

© 2013 Teledyne LeCroy, Inc. All rights reserved. Unauthorized duplication of Teledyne LeCroy documentation materials other than for internal sal

DA1855A Differential Amplifier 34 922258-00 Rev A two places right of the decimal (10mV) in the Precision Voltage Generator until the positive peak o

Operator’s Manual 922258-00 Rev A 35 • By using the DA1855A in the differential offset mode and the oscilloscope in a high sensitivity setting, high

DA1855A Differential Amplifier 36 922258-00 Rev A The maximum common mode range is ± 15.5 Volt when a signal is applied directly (÷1 ATTENUATOR and n

Operator’s Manual 922258-00 Rev A 37 properly set). Thus, a sine wave large enough to overdrive the DA1855A will appear as a square wave on the oscil

DA1855A Differential Amplifier 38 922258-00 Rev A Care and Maintenance Cleaning Clean only the exterior of the amplifier using a soft cloth moistened

Operator’s Manual 922258-00 Rev A 39 Applications Introduction Some parts of a power supply operation, such as saturation voltage, upper gate drive,

DA1855A Differential Amplifier 40 922258-00 Rev A have a low frequency cut-off of 40 Hz or higher, eliminating the ability to measure power at line f

Operator’s Manual 922258-00 Rev A 41 recovery performance is the oscilloscope or differential amplifier’s probe performance. Probes play an important

DA1855A Differential Amplifier 42 922258-00 Rev A When viewed at 500 m/div, the same 400 V square wave shows the probe compensation to be slightly ov

Operator’s Manual 922258-00 Rev A 43 Figure 7 Saturation Voltage Measurement To measure the saturation voltage of a power device in a flyback type s

Operator’s Manual 922258-00 Rev A i Table of Contents Safety Instructions ...

DA1855A Differential Amplifier 44 922258-00 Rev A Gate Drive Voltage The main reason to measure the gate drive voltage is to assure rapid turn-on and

Operator’s Manual 922258-00 Rev A 45 Rejecting the AC line voltage was no real challenge, but rejecting the drain to source signal is a real measure

DA1855A Differential Amplifier 46 922258-00 Rev A Remote Control Commands When attached to a Teledyne LeCroy oscilloscope equipped with ProBus interf

Operator’s Manual 922258-00 Rev A 47 Gain Control Mode The DA1855A amplifiers have two modes for setting the amplifier gain and attenuation; Auto and

DA1855A Differential Amplifier 48 922258-00 Rev A Auto-Zero PRx:AUTOZERO, PRx:AZ Command Description The PRx:AUTOZERO command initiates an auto zer

Operator’s Manual 922258-00 Rev A 49 Coupling PRx:COUPLING, PRx:CPL Command/query Description The PRx:COUPLING command sets the input coupling for

DA1855A Differential Amplifier 50 922258-00 Rev A Gain PRx:GAIN,PRx:GAI Command/Query Description The PRx:GAIN command sets the differential amplif

Operator’s Manual 922258-00 Rev A 51 Offset PRx:OFFSET, PRx:OFST Command/Query Description The PRx:OFFSET command sets the Precision Voltage Genera

DA1855A Differential Amplifier 52 922258-00 Rev A Input-Resistance PRx:PINPUTR,PRx:PINR Command/Query Description The PRx:PINPUTR command sets the

Operator’s Manual 922258-00 Rev A 53 Probe Attenuation PRx:PROBEATTENUATION?,PRxPATTN? Query Description The PRx:PROBEATTENUATION? query returns th

DA1855A Differential Amplifier ii 922258-00 Rev A Introduction ...

DA1855A Differential Amplifier 54 922258-00 Rev A Precision Voltage Generator PRx:PVGMODE,PRx:PVGM Command Query Description The PRx:PVGMODE comman

Operator’s Manual 922258-00 Rev A 55 Volt / DIV PRx:VOLT_DIV,PRx:VDIV Command/Query Description When used with the "PRx" argument for cha

DA1855A Differential Amplifier 56 922258-00 Rev A Performance Verification This procedure can be used to verify the warranted characteristics of the

Operator’s Manual 922258-00 Rev A 57 Table 5, List of required Equipment Description Minimum Requirements Test Equipment Examples Wide Band Oscillo

DA1855A Differential Amplifier 58 922258-00 Rev A Preliminary Procedure 1. Connect the DA1855A Differential Amplifier to an AC power source within t

Operator’s Manual 922258-00 Rev A 59 Functional Check The functional check will verify the basic operation of the Differential Amplifier functions. I

DA1855A Differential Amplifier 60 922258-00 Rev A 3. Bandwidth Limiting a. Press the 10 MHz BW Limit button on the front panel of the DA1855A and v

Operator’s Manual 922258-00 Rev A 61 Figure 9, X1 Gail Accuracy j. Press the X1 GAIN button to remove any residual DC offset from the input. (A DC

DA1855A Differential Amplifier 62 922258-00 Rev A 2. Check X10 Gain Accuracy NOTE: Because most DMMs do not provide the required accuracy on lower A

Operator’s Manual 922258-00 Rev A 63 Figure 10, X10 Gain Accuracy Setup. h. Remove the DMM cable from the BNC Tee and from the banana plug adapter

Operator’s Manual 922258-00 Rev A 1 Safety Instructions This section contains instructions that must be observed to keep this oscilloscope accessory

DA1855A Differential Amplifier 64 922258-00 Rev A k. Divide the DMM reading in step 2-j into the output amplitude measured in step 2-g. This is the

Operator’s Manual 922258-00 Rev A 65 Figure 13, X10 Gain Accuracy Setup v. Divide the sine wave generator output voltage recorded in step 2-q by th

DA1855A Differential Amplifier 66 922258-00 Rev A 3. Check ÷10 Attenuator Accuracy a. Remove the DA1855A output cable/precision termination from th

Operator’s Manual 922258-00 Rev A 67 Figure 15, ÷10 Attenuator Accuracy Setup. l. Press the X1 GAIN button to autozero the amplifier. m. After the

DA1855A Differential Amplifier 68 922258-00 Rev A 4. Check X1 Bandwidth and Calculate Rise Time a. Connect the DA1855A AMPLIFIER OUTPUT to channel 1

Operator’s Manual 922258-00 Rev A 69 i. Set the sine wave generator output frequency to 50 MHz. Be careful not to alter the output amplitude. NOTE:

DA1855A Differential Amplifier 70 922258-00 Rev A b. Set the DA1855A GAIN to X1, ATTENUATOR to ÷1. c. Set the leveled sine wave generator output fr

Operator’s Manual 922258-00 Rev A 71 j. Verify that the channel 1 input coupling is set to DC and 1MΩ. k. Set the oscilloscope to display channel 1

DA1855A Differential Amplifier 72 922258-00 Rev A s. Verify that the oscilloscope is set to display channel 1 and the\ input coupling to DC and 50Ω.

Operator’s Manual 922258-00 Rev A 73 b. Connect a BNC cable from the Frequency Reference Signal Output of the leveled sine wave generator to the Ext

DA1855A Differential Amplifier 2 922258-00 Rev A  Use indoors only.  Keep product surfaces clean and dry.  Do not block the cooling vents. Leav

DA1855A Differential Amplifier 74 922258-00 Rev A k. Set the oscilloscope to display channel 1, coupling to DC and impedance to 50 Ω and the vertica

Operator’s Manual 922258-00 Rev A 75 o. Calculate the Common Mode Rejection ratio (CMRR) at70 Hz by dividing the Differential Mode Gain at 70 Hz (1.

DA1855A Differential Amplifier 76 922258-00 Rev A aa. 100 kHz by dividing the Differential Mode gain at 70 Hz (1.0)by the Common Mode Gain recorded i

Operator’s Manual 922258-00 Rev A 77 Performance Verification Test Record This record can be used to record the results of measurements made during t

DA1855A Differential Amplifier 78 922258-00 Rev A DA1855A Test Record Step Description Intermediate data Test Result X1 Gain Accuracy 1-f Sine

Operator’s Manual 922258-00 Rev A 79 High Frequency CMRR Step Description Intermediate data Test Result 5-e Amplifier Output Voltage at 10 MHz

DA1855A Differential Amplifier 80 922258-00 Rev A Reference Differential Mode and Common Mode Differential amplifiers amplify the voltage difference

Operator’s Manual 922258-00 Rev A 81 The common mode frequency in these graphs is assumed to be sinusoidal. In real life applications, the common mod

DA1855A Differential Amplifier 82 922258-00 Rev A Certifications This section certifies the instrument’s Electromagnetic Compatibility (EMC), Safety

Operator’s Manual 922258-00 Rev A 83 European Contact: Teledyne LeCroy Europe GmbH Waldhofer Str 104 D-69123 Heidelberg Germany Tel: (49) 6221 82700

Operator’s Manual 922258-00 Rev A 3 Calibration The amplifier is calibrated at the factory prior to being shipped. The recommended calibration interv

DA1855A Differential Amplifier 84 922258-00 Rev A  Protection Class I: grounded equipment in which protection against electric shock is achieved by

Operator’s Manual 922258-00 Rev A 85 Returning a Product Contact your local Teledyne LeCroy sales representative to find out where to return the prod

DA1855A Differential Amplifier 86 922258-00 Rev A Contact Teledyne LeCroy Teledyne LeCroy Service Centers United States and Canada - World Wide Corp