US 9,813,063 B2
Method of using a field-effect transistor as a current sensing device
Gary L. Stirk, West Melbourne, FL (US); and Karthik Kadirvel, San Jose, CA (US)
Assigned to Apple Inc., Cupertino, CA (US)
Filed by Apple Inc., Cupertino, CA (US)
Filed on May 6, 2015, as Appl. No. 14/705,600.
Claims priority of provisional application 62/096,323, filed on Dec. 23, 2014.
Prior Publication US 2016/0178705 A1, Jun. 23, 2016
Int. Cl. H03K 19/0175 (2006.01); G01R 31/36 (2006.01); H02J 7/00 (2006.01); H03L 7/00 (2006.01); G06F 13/42 (2006.01)
CPC H03K 19/017509 (2013.01) [G01R 31/3655 (2013.01); G01R 31/3675 (2013.01); H02J 7/007 (2013.01); H02J 7/0026 (2013.01); H02J 7/0052 (2013.01); H02J 7/0068 (2013.01); H03L 7/00 (2013.01); G06F 13/4256 (2013.01); H02J 7/0021 (2013.01); H02J 2007/0059 (2013.01); Y02B 60/1228 (2013.01); Y02B 60/1235 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An apparatus comprising:
one or more registers;
an analog-to-digital converter (ADC) configured to generate a first digital value corresponding to a difference in voltage levels between a first terminal and a second terminal of a transistor;
a sensor configured to measure a temperature; and
control logic configured to:
generate a control voltage level at a control terminal of the transistor;
receive the first digital value from the ADC;
read at least one value of a plurality of values stored in the one or more registers, wherein the plurality of values correspond to a characteristic of the transistor at a respective one of a plurality of temperatures;
during a first operational mode, determine, based on the first digital value, the at least one value of the plurality of values, and the temperature, a current passing through the transistor; and
during a second operational mode, update, based on the temperature, one or more values of the plurality of values.