US 12,241,939 B2
Estimation of unknown electronic load
William C. Weeman, Aurora, OH (US)
Assigned to Keithley Instruments, LLC, Solon, OH (US)
Filed by Keithley Instruments, LLC, Solon, OH (US)
Filed on Aug. 16, 2023, as Appl. No. 18/450,692.
Application 18/450,692 is a continuation of application No. 16/894,633, filed on Jun. 5, 2020, granted, now 11,768,248.
Claims priority of provisional application 62/863,809, filed on Jun. 19, 2019.
Prior Publication US 2023/0393213 A1, Dec. 7, 2023
Int. Cl. G01R 31/3842 (2019.01); G01R 31/30 (2006.01); G01R 31/319 (2006.01); G01R 35/00 (2006.01)
CPC G01R 31/3842 (2019.01) [G01R 31/3004 (2013.01); G01R 31/31924 (2013.01); G01R 35/005 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A method for estimating an unknown load coupled to a test and measurement instrument, comprising:
acquiring a voltage at a circuit node between a current sensor and a device under test, wherein the device under test presents the unknown load to the test and measurement instrument;
determining an output voltage forced on the current sensor;
determining a current through the device under test using the current sensor;
iteratively updating an estimation of the unknown load based on the voltage at the circuit node, the current, and the output voltage, wherein the estimation of the unknown load is adjusted upwards or downwards at each subsequent iteration; and
adjusting behavior of the test and measurement instrument based on the updated estimation of the unknown load.