US 11,705,890 B2
Programmable analog calibration circuit supporting iterative measurement of an input signal from a measured circuit, such as for calibration, and related methods
Anirban Banerjee, Cary, NC (US); Bupesh Pandita, Cary, NC (US); Charles Boecker, Ames, IA (US); and Eric Groen, Ankeny, IA (US)
Assigned to Microsoft Technology Licensing, LLC, Redmond, WA (US)
Filed by Microsoft Technology Licensing, LLC, Redmond, WA (US)
Filed on Aug. 26, 2021, as Appl. No. 17/412,879.
Prior Publication US 2023/0060647 A1, Mar. 2, 2023
Int. Cl. H03K 3/011 (2006.01); H03K 3/017 (2006.01); H03K 5/24 (2006.01); G06F 1/06 (2006.01)
CPC H03K 3/011 (2013.01) [G06F 1/06 (2013.01); H03K 3/017 (2013.01); H03K 5/24 (2013.01)] 34 Claims
OG exemplary drawing
 
1. An analog calibration (ACAL) circuit, comprising:
a programmable voltage reference generation circuit configured to:
generate a step reference voltage among a plurality of programmable step reference voltages based on a supply voltage and a reference voltage programming selection selected by a reference voltage selection circuit;
the ACAL circuit configured to generate an input reference voltage based on the selected step reference voltage;
further comprising:
a comparator circuit configured to:
compare the input reference voltage to an input circuit voltage from a measured circuit; and
generate a digital measurement signal based on a difference between the input reference voltage and the input circuit voltage; and
the ACAL circuit further configured to:
determine if the input reference voltage is greater than the input circuit voltage based on the digital measurement signal; and
in response to the digital measurement signal indicating the input reference voltage is greater than the input circuit voltage:
generate a next step reference voltage among the plurality of programmable step reference voltages based on the supply voltage and a next reference voltage programming selection; and
generate the input reference voltage based on the next selected step reference voltage.