Source measure unit with guard drive circuit
AssigneeKeithley Instruments, LLC
InventorsJames A. Niemann, Wayne C. Goeke
Life of this patent
Estimating the term…
Abstract
A test and measurement device including a source configured to output a source signal, a source output configured to output the source signal to a connected cable, a guard drive circuit electrically coupled to the source and configured to receive the source signal and generated a guard drive signal, the guard drive circuit having a gain less than one, and a guard drive circuit output configured to output the guard drive signal to a connected guard.
Claims20
A test and measurement device, comprising:
- a source configured to output a source signal;
- a source output configured to output the source signal to a connected cable;
- a guard drive circuit electrically coupled to the source and configured to receive the source signal and generate a guard drive signal, the guard drive circuit having a gain less than one;
- and
- a guard drive circuit output configured to output the guard drive signal to a connected guard.
A method for driving a guard of a cable connected to a test and measurement instrument, comprising:
- generating a source signal;
- outputting the source signal to an output terminal configured to be connected to the cable;
- and
- generating a guard drive signal based on the source signal by attenuating the source signal using a guard drive circuit having a gain of less than one.
A test and measurement device, comprising:
- a source configured to generate a source signal;
- a port configured to electrically couple to a cable and a guard of the cable;
- and
- a guard drive circuit configured to output a guard drive signal through the port to the guard of the cable, the guard drive circuit including:
- a first operational amplifier configured to receive the source signal and output a signal based on the source signal;
- an attenuator circuit electrically coupled to the first operational amplifier and
- configured to receive the signal from the first operational amplifier and reduce a magnitude of
- the signal received from the first operational amplifier;
- and
- a second operational amplifier electrically coupled to the attenuator circuit and configured to receive a signal from the attenuator circuit and output the guard drive signal.
Dependencies are inferred from the claim text.