US 12,487,262 B2
Systems and methods for PLP capacitor health check
Timothy Simon Butler, Didcot (GB); and Paul Abrahams, San Jose, CA (US)
Assigned to KIOXIA CORPORATION, Tokyo (JP)
Filed by Kioxia Corporation, Tokyo (JP)
Filed on May 22, 2023, as Appl. No. 18/321,340.
Application 18/321,340 is a continuation of application No. 16/775,138, filed on Jan. 28, 2020, granted, now 11,656,257.
Prior Publication US 2023/0288464 A1, Sep. 14, 2023
Int. Cl. G01R 27/26 (2006.01); G01R 31/30 (2006.01); G06F 1/30 (2006.01); G11C 29/02 (2006.01)
CPC G01R 27/2688 (2013.01) [G01R 31/3004 (2013.01); G06F 1/30 (2013.01); G11C 29/02 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A method for managing a power-loss protection (PLP) capacitor, comprising:
obtaining, using a test circuit coupled to the capacitor, a plurality of recent leakage current test results for the capacitor at a respective plurality of different past times within a lifetime of the capacitor;
storing, in a memory device, the plurality of recent leakage current test results;
determining a present upper limit and a present lower limit based on the plurality of recent leakage current test results;
comparing the present upper limit and the present lower limit to upper and lower thresholds, respectively;
providing, by a processing circuit coupled to the test circuit, an indication that the capacitor is unsuitable for use in power-loss protection in response to determining that the present upper limit is greater than the upper threshold or the present lower limit is less than the lower threshold; and
determining each of the recent leakage current test results, including:
determining a first drain current using a first load and determining a second drain current using a second load;
determining a first time interval needed for a voltage across the first load to drop a predetermined voltage; and
determining a second time interval needed for a voltage across the second load to drop the predetermined voltage,
wherein determining each of the recent leakage current test results is based at least on the first drain current, the second drain current, the first time interval, and the second time interval.