Active shunt source-measure unit (SMU) circuit

Patent metadata

Field	Value
Publication number	US-9453880-B2
Application number	US-201414163725-A
Country	US
Kind code	B2
Filing date	Jan 24, 2014
Priority date	Jan 24, 2014
Publication date	Sep 27, 2016
Grant date	Sep 27, 2016

Abstract

An active shunt source-measure unit (SMU) circuit can include an SMU or power supply having an active shunt circuit that is integrated with the current measuring sub-circuit of the SMU circuit. The active shunt circuit may be active during voltage sourcing of the SMU circuit and deactivated during current sourcing of the SMU circuit.

First claim

We claim:

1. A circuit for sourcing voltage and current to a device under test (DUT), the circuit comprising:
an output configured to be electrically coupled with the DUT; and
a power-providing circuit electrically coupled with the output, the power-providing circuit comprising:
at least one sense resistor in series with the output, the at least one sense resistor including a first resistor R 0 having a first end electrically coupled with the output;
a first capacitor C 0 electrically coupled in parallel with the first resistor R 0 ;
a first amplifier electrically coupled with the output;
a second amplifier electrically coupled between the output and a first switch;
a first gain stage amplifier electrically coupled between the output and a second switch;
a second gain stage amplifier electrically coupled between the output and the first gain stage amplifier;
a second resistor R 1 electrically coupled between the third amplifier and the first resistor R 0 ; and
a second capacitor C 1 electrically coupled in parallel with the second resistor R 1 .

2. The circuit of claim 1 , further comprising two resistors R A and R B added as feedback to the first and second gain stage amplifiers.

3. The circuit of claim 1 , wherein the resistance of the second resistor R 1 is defined by the following:
R 1 =( k− 1) R 0

4. The circuit of claim 1 , wherein the capacitance of the second capacitor C 1 is defined by the following:
C 1 =C 0 /( k− 1)

5. The circuit of claim 1 , wherein the first switch is configured to toggle a buffer that is electrically coupled with the output.

6. The circuit of claim 5 , wherein the second switch is configured to toggle the buffer, and further wherein no more than one of the first and second switches is electrically coupled with the buffer at any given time.

7. The circuit of claim 5 , wherein the second switch is configured to toggle a buffer that is electrically coupled with the output.

Assignees

• Keithley Instruments

Inventors

• Goeke Wayne C

Classifications

• G01R1/203

  Resistors used for electric measuring, e.g. decade resistors standards, resistors for comparators, series resistors, shunts (resistors in general H01C; microwave or radiowave terminations H01P1/26; coupling devices H01R) · CPC title

• G01R31/31721 Primary

  Power aspects, e.g. power supplies for test circuits, power saving during test (for scan test G01R31/318575) · CPC title