# US 11,444,451 B2 · Fast current transient suppression in a test system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,444,451 B2 - Document ID: US11444451B2 - Status: Granted - Kind: B2 - Application number: 16/736,601 - Filed: 2020-01-07 - Published: 2020-07-30 - Granted: 2022-09-13 - Earliest claimed: 2019-01-27 - Assignees: Keithley Instruments, LLC - Applicants: Keithley Instruments, LLC - Inventors: Arthur Sypen - Web page: https://patentgrep.com/patent/US11444451B2 ## CPC - H02H 9/005: {avoiding undesired transient conditions} - H02H 1/0007: {concerning the detecting means (in general G01R or other subclasses of G01; reed switches H01H71/2445)} - H02H 9/02: responsive to excess current {(current limitation for voltage regulators G05F1/573; disconnection after limiting H02H3/025)} - G01R 1/36: Overload-protection arrangements or circuits for electric measuring instruments - H02H: EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS (indicating or signalling undesired working conditions G01R, e.g. G01R31/00, G08B; locating faults along lines G01R31/08; emergency protective devices H01H) - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) ## Abstract A current transient suppression circuit includes an inductor electrically connected to a test signal by an input of the inductor, at least one switching device electrically connected to an output of the inductor, and an output of the at least one switching device connected to a shunt path. A method of suppressing current transients in a circuit includes receiving a test signal at an inductor, and when the test signal comprises a current transient, the current transient is received at the inductor, activating at least one switching device electrically connected to the inductor to shunt the current transient away from a device under test. ## Claims ### Claim 1 A current transient suppression circuit, comprising: an inductor electrically connected to a test signal by an input of the inductor; at least one switching device electrically connected to an output of the inductor; an output of the at least one switching device connected to a shunt path; and a bridge rectifier electrically connected to an output of the inductor between the output of the inductor and the at least one switching device. ### Claim 2 (depends on 1) The circuit as claimed in claim 1, wherein the inductor comprises a stand-alone inductor. ### Claim 3 (depends on 1) The circuit as claimed in claim 1, further comprising a resistor-capacitor network electrically connected between the bridge rectifier and the at least one switching device. ### Claim 4 (depends on 1) The circuit as claimed in claim 1, further comprising a transformer electrically connected between the output of the inductor and the bridge rectifier. ### Claim 5 (depends on 1) The circuit as claimed in claim 1, further comprising a bidirectional diode combination electrically connected between the output of the inductor and the bridge rectifier. ### Claim 6 (depends on 1) The circuit as claimed in claim 1, wherein the at least one switching device comprises at least one transistor. ### Claim 7 A current transient suppression circuit, comprising: an inductor electrically connected to a test signal by an input of the inductor; at least one switching device electrically connected to an output of the inductor; an output of the at least one switching device connected to a shunt path; and a guard circuit between the test signal and the at least one switching device. ### Claim 8 A current transient suppression circuit, comprising: an inductor electrically connected to a test signal by an input of the inductor, wherein the inductor comprises a primary winding of a transformer; at least one switching device electrically connected to an output of the inductor; and an output of the at least one switching device connected to a shunt path. ### Claim 9 (depends on 8) The circuit as claimed in claim 8, further comprising a bridge rectifier electrically connected to an output of the transformer. ### Claim 10 (depends on 9) The circuit as claimed in claim 9, further comprising a bidirectional diode combination electrically connected between the bridge rectifier and the at least one switching device. ### Claim 11 (depends on 10) The circuit as claimed in claim 10, further comprising a resistor-capacitor network between the bidirectional diode combination and the switching device. ### Claim 12 A method of suppressing current transients in a circuit, comprising: receiving a test signal at an inductor; when the test signal comprises a current transient, the current transient is received at the inductor, activating at least one switching device electrically connected to the inductor to shunt the current transient away from a device under test; and providing a bridge rectifier electrically connected to an output of the inductor to allow bipolar operation. ### Claim 13 (depends on 12) The method as claimed in claim 12, wherein providing the bridge rectifier comprises connecting the output of the inductor to a transformer and connecting an output of the transformer to a bridge rectifier. ### Claim 14 (depends on 12) The method as claimed in claim 12, wherein the current transient comprises a transient current generated from a source of the test signal. ### Claim 15 (depends on 12) The method as claimed in claim 12, wherein the current transient comprises a current generated in response to conduction of the device under test. ### Claim 16 (depends on 12) The method as claimed in claim 12, wherein receiving the test signal at an inductor comprises receiving the test signal at a stand-alone inductor. ### Claim 17 (depends on 12) The method as claimed in claim 12, wherein receiving the test signal at an inductor comprises receiving the test signal at a primary winding of a transformer. ### Claim 18 A method of suppressing current transients in a circuit, comprising: receiving a test signal at an inductor; when the test signal comprises a current transient, the current transient is received at the inductor, activating at least one switching device electrically connected to the inductor to shunt the current transient away from a device under test; and providing a guard circuit electrically connected to a source of the test signal.