LeCroy DA18000, Instruction Manual

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DA18000 Differential Amplifier
4-4
DA18000-OM-E Rev A
USE OF DC
÷
2 ATTENUATOR
The
÷
2 attenuator should be used when the common mode or differential voltage of the cir-
cuit under test is unknown or exceeds the maximum voltage specified. (See section 9, Spec-
ifications). The use of the attenuator will also reduce the reflections, thus improving the
VSWR.
The DA18000 amplifier has no method to detect the presence or absence of the attenuator.
To maintain correct vertical scale factor and amplitude measurement results, you must
inform the oscilloscope when the attenuator is being used. This is done in the
Vertical
Adjust
→
DA18000 control dialog for the channel that the amplifier is connected to.
DYNAMIC RANGE
The DA18000 amplifier has no gain or attenuation control. The system gain is fixed at x1.
Exceeding the common mode range may introduce distortion to the output signal. Use of the
÷
2 attenuators will increase the differential mode range; however, due to power limitations,
they will not increase the common mode range.
There are two common mode voltages:
±10 V without a
÷
2 attenuator
7 V
rms
with a
÷
2 attenuator
§ § §