Teledyne LeCroy AP033 - Manual (Page 17)

Operator’s Manual
922260-00 Rev A 11
The best recommendation for connecting or not connecting the probe ground is to try both
configurations and select the one that performs the best.
NOTE The AP033 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 AP033 has two independent controls that set the common mode range and equivalent
volts/division. The probe gain can be set to x1 or x10. The gain control (GAIN) only affects the
differential mode range of the probe. A separate input attenuation control (ATTEN) sets the probe
input attenuator to either

÷

or ÷ 10. See Figure 3.
Figure 3, AP033 Block Diagram
The attenuator is located at the probe input and, therefore, affects both the differential mode and
common mode ranges. (Refer to the Reference Section for definitions of Common Mode and
Differential Mode.) By using the plug-on attenuator, you can extend the attenuation range to
÷ 100.
The maximum ranges are given in Table 1.