Teledyne DA1855A, Operator'S Manual

Page: 37 / 94

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 wave of 50
kHz and 1.0 Vp-p amplitude. The signal on the oscilloscope should be 2 divisions peak to peak
amplitude. Adjust the oscilloscope’s time per division and trigger to display at least two complete
cycles of the waveform.
Press the ÷1 ATTENUATOR button on non-ProBus operated systems or selecting Atten in the List
Select menu and setting the attenuation to /1 in systems with ProBus interface. The waveform’s
magnitude on the oscilloscope’s display will increase by a factor of 10 and extend off the top and
bottom of the screen.
The X1 light will be lighted in the EFFECTIVE GAIN display. Reduce the function generator’s output
until the oscilloscope’s display is again 2 divisions peak to peak. The overall sensitivity of the
DA1855A and the oscilloscope is now 50 mV/div.
Now press the X10 GAIN button. Observe the following changes: The +INPUT’s DC light will
momentarily go out and its OFF light will be lighted before returning to their previous states. This
momentary change is the result of the DA1855A automatically adjusting its DC Balance. The X10
light will be lighted in the EFFECTIVE GAIN display and the display on the oscilloscope will again
extend off screen. The overall sensitivity of the DA1855A and the oscilloscope is now 5 mV/div.
Comparison Voltage Operation (V
COMP
)
Leave the DA1855A set up as in the previous exercise or set as follows:
+INPUT
DC
–INPUT
OFF
BW LIMIT
FULL
GAIN
X10
ATTENUATOR ÷ ÷1
INPUT RESISTANCE
1MΩ
PVG +00.00
COMPARISON or
DIFFERENTIAL
COMPARISON
EFFECTIVE GAIN
X10
Set the Function generator’s output to 50 kHz and 100 mVp-p sine wave and the output connected
to the DA1855’s +INPUT.
Set the oscilloscope to 50 mV/div (equivalent to 5 mV/div with DA1855A set at X10 GAIN) and
time/div adjusted for 2 to 3 cycles.
Under these conditions, the display on the oscilloscope will extend off the top and bottom of the
screen.