# US 11,442,520 B2 · Determination of one or more operating parameters for a switched-mode power supply > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,442,520 B2 - Document ID: US11442520B2 - Status: Granted - Kind: B2 - Application number: 17/167,587 - Filed: 2021-02-04 - Published: 2021-05-27 - Granted: 2022-09-13 - Earliest claimed: 2017-09-08 - Assignees: Texas Instruments Incorporated - Applicants: Texas Instruments Incorporated - Inventors: Pradeep Kumar Chawda; Ning Dong; Makram Monzer Mansour; Jeffrey Robert Perry - Web page: https://patentgrep.com/patent/US11442520B2 ## CPC - G06F 1/28: Supervision thereof, e.g. detecting power-supply failure by out of limits supervision - G01R 31/40: Testing power supplies (testing photovoltaic devices H02S50/10) - G06F 1/26: Power supply means, e.g. regulation thereof (for memories G11C) - G06F 1/3296: by lowering the supply or operating voltage - G01R 19/16528: {using digital techniques or performing arithmetic operations (using digital techniques to measure a voltage or a current, see G01R19/25)} - G01R 19/2506: {Arrangements for conditioning or analysing measured signals, e.g. for indicating peak values (G01R19/003 takes precedence); Details concerning sampling, digitizing or waveform capturing (displaying waveforms G01R13/00; analog sampling G01R19/0053)} - G06F 17/142: {Fast Fourier transforms, e.g. using a Cooley-Tukey type algorithm} - G06F 2218/02: Preprocessing - G06F 2218/08: Feature extraction - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) ## Abstract A method includes obtaining a first waveform representing an output characteristic with respect to time of a switched-mode power supply. The method further includes removing a high frequency component from the first waveform to generate a modified waveform and determining a stable value of the modified waveform. The method further includes determining an operating parameter of the switched-mode power supply based on the modified waveform, the stable value, or a combination thereof. The one or parameter includes an overshoot value associated with the switched-mode power supply, an undershoot value associated with the switched-mode power supply, or a settling time associated with the switched-mode power supply. The method further includes outputting an indication of the parameter. ## Claims ### Claim 1 A method of measuring operating parameters for a switched-mode power supply, comprising: obtaining from a sensor an output waveform representing an output of the switched-mode power supply over a time window at a transition of that output from a first output level to a second output level; removing a high frequency component from the output waveform to generate a modified waveform; determining a stable value of the modified waveform over a portion of the time window by at least: determining an error band based on the output waveform; and identifying a first time at which a voltage level of the modified waveform exceeds or is less than the error band, wherein the portion of the time window is bounded by the first time; determining, based on the modified waveform and the stable value, an overshoot value at the output of the switched-mode power supply and an undershoot value at the output of the switched-mode power supply; and outputting indications of the overshoot and undershoot values. ### Claim 2 (depends on 1) The method of claim 1, wherein removing the high frequency component comprises: transforming the output waveform into a frequency domain waveform by applying a fast Fourier transform to the output waveform; applying a low pass filter to the frequency domain waveform to generate a filtered waveform; and transforming the filtered waveform into time domain by applying an inverse fast Fourier transform to the filtered waveform. ### Claim 3 (depends on 1) The method of claim 1, wherein removing the high frequency component comprises: transforming the output waveform into a frequency domain waveform; calculating a least-square linear fitting of the frequency domain waveform; and subtracting the least-square linear fitting from the frequency domain waveform to generate a detrended waveform. ### Claim 4 (depends on 3) The method of claim 3, wherein removing the high frequency component further comprises: identifying a preselected number of highest peaks in a second half of the detrended waveform; identifying a lowest dip in the detrended waveform before a first peak of the identified highest peaks, the lowest dip having a particular frequency value; and generating a filtered waveform by setting spectrum beyond the particular frequency value to zero. ### Claim 5 (depends on 1) The method of claim 1, further comprising: determining, based on the modified waveform and the stable value, a value of a settling time at the output of the switched-mode power supply; and outputting an indication of the settling time value. ### Claim 6 (depends on 1) The method of claim 1, wherein determining the stable value further comprises identifying a second time associated with the transition from the first output level to the second output level, and wherein the portion of the time window is bounded by the first and second times. ### Claim 7 (depends on 1) The method of claim 1, wherein determining the stable value further comprises: identifying a second time associated with the transition from the first output level to the second output level; calculating a first peak-to-peak ripple for a first sub-window proximate the second time; calculating a second peak-to-peak ripple for a second sub-window proximate the first sub-window; and establishing the portion of the time window to not include the first sub-window in response to determining that the first peak-to-peak ripple is greater than the second peak-to-peak ripple. ### Claim 8 (depends on 1) The method of claim 1, wherein determining the error band comprises determining a voltage range of the error band based on a heuristic analysis of the output waveform. ### Claim 9 A non-transitory computer readable storage device storing instructions that, when executed by one or more processors, cause the one or more processors to measure operating parameters for a switched-mode power supply by a plurality of operations comprising: obtaining from a sensor an output waveform representing an output of the switched-mode power supply over a time window at a transition of that output from a first output level to a second output level; removing a high frequency component from the output waveform to generate a modified waveform; determining a stable value of the modified waveform over a portion of the time window by at least: determining an error band based on the output waveform; and identifying a first time at which a voltage level of the modified waveform exceeds or is less than the error band, wherein the portion of the time window is bounded by the first time; determining, based on the modified waveform and the stable value, an overshoot value at the output of the switched-mode power supply and an undershoot value at the output of the switched-mode power supply; and outputting indications of the overshoot and undershoot values. ### Claim 10 (depends on 9) The computer readable storage device of claim 9, wherein removing the high frequency component comprises: transforming the output waveform into a frequency domain waveform by applying a fast Fourier transform to the output waveform; applying a low pass filter to the frequency domain waveform to generate a filtered waveform; and transforming the filtered waveform into time domain by applying an inverse fast Fourier transform to the filtered waveform. ### Claim 11 (depends on 9) The computer readable storage device of claim 9, wherein removing the high frequency component comprises: transforming the output waveform into a frequency domain waveform; calculating a least-square linear fitting of the frequency domain waveform; and subtracting the least-square linear fitting from the frequency domain waveform to generate a detrended waveform. ### Claim 12 (depends on 11) The computer readable storage device of claim 11, wherein removing the high frequency component further comprises: identifying a preselected number of highest peaks in a second half of the detrended waveform; identifying a lowest dip in the detrended waveform before a first peak of the identified highest peaks, the lowest dip having a particular frequency value; and generating a filtered waveform by setting spectrum beyond the particular frequency value to zero. ### Claim 13 (depends on 9) The computer readable storage device of claim 9, wherein the instructions further cause the one or more processors to receive a search query indicating a parameter criterion, wherein the indications are output in response to an operating parameter satisfying the parameter criterion. ### Claim 14 (depends on 9) The computer readable storage device of claim 9, wherein the instructions further cause the one or more processors to: determine, based on the modified waveform and the stable value, a value of a settling time at the output of the switched-mode power supply; and output an indication of the settling time value. ### Claim 15 (depends on 9) The computer readable storage device of claim 9, wherein determining the stable value further comprises identifying a second time associated with the transition from the first output level to the second output level, and wherein the portion of the time window is bounded by the first and second times. ### Claim 16 (depends on 9) The computer readable storage device of claim 9, wherein determining the stable value further comprises: identifying a second time associated with the transition from the first output level to the second output level; calculating a first peak-to-peak ripple for a first sub-window proximate the second time; calculating a second peak-to-peak ripple for a second sub-window proximate the first sub-window; and establishing the portion of the time window to not include the first sub-window in response to determining that the first peak-to-peak ripple is greater than the second peak-to-peak ripple. ### Claim 17 An apparatus configured to measure operating parameters for a switched-mode power supply, the apparatus comprising: one or more processors; and a memory storing instructions that, when executed by the one or more processors, cause the one or more processors to: obtain from a sensor an output waveform representing an output of the switched-mode power supply over a time window at a transition of that output from a first output level to a second output level; generate a modified waveform by removing a high frequency component from the output waveform; determine a stable value of the modified waveform over a portion of the time window by at least: determining an error band based on the output waveform; and identifying a first time at which a voltage level of the modified waveform exceeds or is less than the error band, wherein the portion of the time window is bounded by the first time; determine, based on the modified waveform and the stable value, an overshoot value at the output of the switched-mode power supply and an undershoot value the switched-mode power supply; and output indications of the overshoot and undershoot values. ### Claim 18 (depends on 17) The apparatus of claim 17, wherein the sensor comprises a voltage sensor configured to measure voltage generated by the switched-mode power supply, wherein obtaining the output waveform includes receiving the output waveform from the voltage sensor. ### Claim 19 (depends on 17) The apparatus of claim 17, wherein removing the high frequency component comprises: transforming the output waveform into a frequency domain waveform applying a fast Fourier transform to the output waveform; applying a low pass filter to the frequency domain waveform to generate a filtered waveform; and transforming the filtered waveform into the time domain by applying an inverse fast Fourier transform to the filtered waveform. ### Claim 20 (depends on 17) The apparatus of claim 17, wherein the instructions further cause the one or more processors to: determine, based on the modified waveform and the stable value, a value of a settling time at the output of the switched-mode power supply; and output an indication of the settling time value.