# US 12,113,542 B2 · Calibration detector with two offset compensation loops > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,113,542 B2 - Document ID: US12113542B2 - Status: Granted - Kind: B2 - Application number: 17/892,001 - Filed: 2022-08-19 - Published: 2024-02-22 - Granted: 2024-10-08 - Earliest claimed: 2022-08-19 - Assignees: Avago Technologies International Sales Pte. Limited - Applicants: Avago Technologies International Sales Pte. Limited - Inventors: Jan Mulder; Frank Van der Goes; Mohammadreza Mehrpoo; Sijia Wang; Jeffrey Allan Riley - Web page: https://patentgrep.com/patent/US12113542B2 ## CPC - H03M 1/1023: {Offset correction (H03M1/1019 takes precedence; removal of offset already present on the analogue input signal H03M1/1295)} - H03M 1/742: {using current sources as quantisation value generators} - H03M 1/0863: {of switching transients, e.g. glitches} - H03M 1/68: with conversions of different sensitivity, i.e. one conversion relating to the more significant digital bits and another conversion to the less significant bits - H03M 1/785: {using resistors, i.e. R-2R ladders} - H03M: CODING; DECODING; CODE CONVERSION IN GENERAL (using fluidic means F15C4/00; optical analogue/digital converters G02F7/00; coding, decoding or code conversion, specially adapted for particular applications, see the relevant subclasses, e.g. G01D, G01R, G06F, G06T, G09G, G10L, G11B, G11C, H04B, H04L, H04M, H04N; ciphering or deciphering for cryptography or other purposes involving the need for secrecy G09C) ## Abstract Described herein are related to a calibration circuit for a digital to analog converter (DAC) including a plurality of DAC cells. The calibration circuit including a chopper circuit configured to receive a first signal from a first DAC cell of the plurality of DAC cells and receive a second signal from a second DAC cell of the plurality of DAC cells. The calibration circuit including a comparator circuit configured to receive the first signal and the second signal from the chopper circuit, provide a third signal indicating at least one of the first signal or the second signal. The calibration circuit also including a second circuit configured to offset a first voltage associated with the comparator circuit and configured to offset a second voltage associated with the chopper circuit. ## Claims ### Claim 1 A calibration system for a circuit in an integrated circuit package, the circuit comprising a plurality of cells, the calibration system comprising: a chopper circuit configured to receive a first signal from a first cell of the plurality of cells and a second signal from a second cell of the plurality of cells; a comparator circuit configured to: receive the first signal and the second signal from the chopper circuit; and provide a third signal indicating at least one of the first signal or the second signal for use in calibration; and a compensation circuit configured to offset a first voltage associated with the comparator circuit and configured to offset a second voltage associated with the chopper circuit; wherein the compensation circuit includes at least one digital to analog convertor cell and at least one chopper circuit. ### Claim 2 (depends on 1) The calibration system of claim 1, wherein the compensation circuit is configured to: determine that the first signal and the second signal are the same; and determine the first voltage associated with the comparator circuit in response to the compensation circuit detecting a third voltage associated with the third signal; wherein the third voltage associated with the third signal indicates the first voltage associated with the comparator circuit. ### Claim 3 (depends on 2) The calibration system of claim 2, wherein the compensation circuit is configured to: provide, in response to the compensation circuit determining the first voltage associated with the comparator circuit, a fourth signal to the comparator circuit; wherein the fourth signal includes a fourth voltage that offsets the first voltage associated with the comparator circuit. ### Claim 4 (depends on 1) The calibration system of claim 1, wherein the compensation circuit is configured to: determine that the first signal and the second signal are the same; and determine the second voltage associated with the chopper circuit in response to the compensation circuit detecting a fifth voltage associated with the third signal; wherein the fifth voltage associated with the third signal indicates the second voltage associated with the chopper circuit. ### Claim 5 (depends on 4) The calibration system of claim 4, wherein the compensation circuit is configured to: provide, in response to the compensation circuit determining the second voltage associated with the chopper circuit, a fifth signal to the chopper circuit; wherein the fifth signal includes a sixth voltage that offsets the second voltage associated with the chopper circuit. ### Claim 6 (depends on 1) The calibration system of claim 1, wherein the compensation circuit is configured to: provide a sixth signal, wherein the sixth signal indicates at least one of the first signal or the second signal; wherein the compensation circuit provides the sixth signal in response to the compensation circuit offsetting the first voltage associated with the comparator circuit. ### Claim 7 (depends on 1) The calibration system of claim 1, wherein the compensation circuit is configured to: provide a seventh voltage that offsets the first voltage associated with the comparator circuit; wherein the seventh voltage includes a first polarity that is different than a second polarity, wherein the first voltage associated with the comparator circuit includes the second polarity. ### Claim 8 (depends on 1) The calibration system of claim 1; wherein the compensation circuit is configured to: provide an eighth voltage that offsets the second voltage associated with the chopper circuit; wherein the eighth voltage includes a third polarity that is different than a fourth polarity, wherein the second voltage associated with the chopper circuit includes the fourth polarity. ### Claim 9 A calibration circuit comprising: a chopper circuit configured to receive a first signal and a second signal; a comparator circuit configured to: receive the first signal and the second signal from the chopper circuit; and provide a third signal indicating at least one of the first signal or the second signal; and a second circuit configured to: provide a first loop to adjust a first offset voltage associated with the comparator circuit and to provide a second loop to adjust a second offset voltage associated with the chopper circuit; determine that the first signal and the second signal are the same; and determine the first offset voltage associated with the comparator circuit in response to the second circuit detecting a first voltage associated with the third signal; wherein the first voltage associated with the third signal indicates the first offset voltage associated with the comparator circuit. ### Claim 10 (depends on 9) The calibration circuit of claim 9, wherein the second circuit further comprises: a third circuit configured to: receive a fourth signal that includes the first offset voltage associated with the comparator circuit; and provide a fifth signal to the comparator circuit, wherein the fifth signal includes a second voltage that offsets the first offset voltage associated with comparator circuit. ### Claim 11 (depends on 9) The calibration circuit of claim 9, wherein the second circuit is configured to: determine that the first signal and the second signal are the same; and determine the second offset voltage associated with the chopper circuit in response to the second circuit detecting a third voltage associated with the third signal; wherein the third voltage associated with the third signal indicates the second offset voltage associated with the chopper circuit. ### Claim 12 (depends on 11) The calibration circuit of claim 11, wherein the second circuit further comprises: a fourth circuit configured to: receive a sixth signal that includes the second offset voltage associated with the chopper circuit; and provide a seventh signal to the chopper circuit, wherein the seventh signal includes a fourth voltage that offsets the second offset voltage associated with the chopper circuit. ### Claim 13 (depends on 9) The calibration circuit of claim 9, wherein the second circuit is configured to: provide an eighth signal, wherein the eighth signal indicates at least one of the first signal or the second signal; wherein the second circuit provides the eighth signal in response to the second circuit providing the first loop and the second loop. ### Claim 14 (depends on 9) The calibration circuit of claim 9, wherein the second circuit further comprises: a third circuit configured to: provide a fifth voltage that offsets the first offset voltage associated with the comparator circuit; wherein the fifth voltage includes a first polarity that is different than a second polarity, wherein the first offset voltage associated with the comparator circuit includes the second polarity. ### Claim 15 (depends on 9) The calibration circuit of claim 9, wherein the second circuit further comprises: a fourth circuit configured to: provide a sixth voltage that offsets the second offset voltage associated with the chopper circuit; wherein the sixth voltage includes a third polarity that is different than a fourth polarity, wherein the second offset voltage associated with the chopper circuit includes the fourth polarity. ### Claim 16 A method of adjusting a calibration circuit, the calibration circuit comprising a comparator, DAC cells, and a chopper circuit, the method comprising: adjusting a first offset voltage associated with the comparator; adjusting a second offset voltage associated with the chopper circuit; and providing, by a third circuit, a first voltage that offsets the first offset voltage associated with the comparator; wherein the first voltage has a first polarity that is different than a second polarity, wherein the first offset voltage associated with the comparator includes the second polarity. ### Claim 17 (depends on 16) The method of claim 16, further comprising: providing, by a fourth circuit, a second voltage that offsets the second offset voltage associated with the chopper circuit; wherein the second voltage has a third polarity that is different than a fourth polarity, wherein the second offset voltage associated with the chopper circuit includes the fourth polarity.