Teledyne LeCroy DA1855A User Manual

Page 82

DA1855A Differential Amplifier

922258-00 Rev A

aa. 100 kHz by dividing the Differential Mode gain at 70 Hz (1.0)by the Common Mode

Gain recorded in step 6-bb. Record the result as ‘Common Mode Rejection Ratio at
100 kHz’ to two significant places in the Test Record. (Keep all of the trailing zeros.)

bb. Check that the CMRR at 100 kHz is greater than 50,000:1(94 dB).

cc. Remove all cables, terminations and adapters from the instruments.

7. Check the Precision Voltage Generator Accuracy

a. Connect a BNC cable from the DA1855A OFFSET VOLTAGE output connector on the

rear panel of the DA1855A to the DMM input. Do not use a 50 Ω termination.

b. Push the PVG ZERO button, located at the lower left side of the Precision Voltage

Generator display.

c. Set the DMM to DC Volts on the most sensitive range. After the display has

stabilized record the reading as ‘PVG Zero Output Voltage’ in the Test Record.

d. Check that the measured 0.0000 V output is within ± 0.5 mV.

e. Set the DMM range to read 15.5 V.

f. Press and hold MSB increment button (button to right of ± button) until the display

reads +15.500V. (If necessary, press the ± button once to invert the polarity.)

g. After the DMM display has stabilized record the reading as PVG Output Voltage at

15.5 V’ in the Test Record with 100 μV resolution.

h. CHECK — That the measured output is within15.4917 to 15.5082 V.

i. Press the ± button to change the output voltage to –15.5000 V.

j. After the DMM display has stabilized record the reading as ‘PVG Output Voltage at –

15.5 V’ in the Test Record with 100 μV resolution.

k. Check that the measured output is within –15.4917 to –15.5082 V.

l. Disconnect DMM and all cables from amplifier.

This completes the Performance Verification Procedure. File the test results as required to support
your internal calibration procedures.