Voltage Probes For Single-Ended Amplifiers - HBM Genesis GEN5i User Manual

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D.2.1

Voltage probes for single-ended amplifiers

Voltage probes divide down a single-ended input signal by a specific factor.
Figure D.8: Typical example of a voltage probe
Voltage probes are – in theory – just passive in-line resistors in front of the
positive input of a single-ended amplifier. Together with the input resistor of the
amplifier they form a voltage divider, so that the voltage in front of the amplifier
itself gets divided down. As there is also a capacitive component in this divider,
the input capacitance of the amplifier and the so called "compensation range"
of the probe need to match, otherwise signal distortion might occur.
By selecting a higher resistance probe the divider ratio gets bigger, so that
pretty large input ranges can be achieved.
Voltage probes do not provide/add either isolation or common mode voltage
rejection.
These probes can only be used in front of single-ended amplifiers.
Voltage probes typically decrease the overall accuracy of the system (caused
by the inaccuracy of the input divider ratio formed by the external probe
resistance and the internal amplifier resistance).
Table C.1: Voltage probes overview table (Part 1)
Part number
(1)
1-G901-2
Divider factor
x1/x10
switchable
GEN5i
Maximum input voltage
1X: 55 V AC rms
10X: 300 V AC rms
I2679-4.0 en