# US 10,122,277 B2 · Method to recover from current loop instability after cycle by cycle current limit intervention in peak current mode control > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,122,277 B2 - Document ID: US10122277B2 - Status: Granted - Kind: B2 - Application number: 15/824,199 - Filed: 2017-11-28 - Published: 2018-03-22 - Granted: 2018-11-06 - Earliest claimed: 2015-12-31 - Assignees: STMicroelectronics S.r.l. - Applicants: STMicroelectronics S.r.l. - Inventors: Andrea Villot; Enrico Papa; Silvio Pepino - Web page: https://patentgrep.com/patent/US10122277B2 ## CPC - H02M 3/158: including plural semiconductor devices as final control devices for a single load - G06F 1/26: Power supply means, e.g. regulation thereof (for memories G11C) - H02M 1/08: Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters - H02M 1/32: Means for protecting converters other than automatic disconnection - H02M 3/156: with automatic control of output voltage or current, e.g. switching regulators - H02M 3/1588: {comprising at least one synchronous rectifier element (H02M3/1582, H02M3/1584 take precedence)} - H02M 1/0009: {Devices or circuits for detecting current in a converter} - Y02B 70/10: Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes - H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P) - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS ## Abstract A method of controlling a switching regulator includes detecting current-limit events indicating a maximum current threshold has been exceeded. A compensation voltage is adjusted in response to the detected current-limit events, where the compensation voltage defines a duty cycle of the switching regulator. A time is detected for which no current-limit events have been detected and the value of the compensation voltage is adjusted to increase the duty cycle of the switching regulator in response to the detected time exceeding a time step threshold. ## Claims ### Claim 1 A method of controlling a switching regulator, comprising: detecting current-limit events indicating a maximum current threshold has been exceeded; adjusting a value of a compensation voltage in response to the detected current-limit events, the compensation voltage defining a duty cycle of the switching regulator; detecting a time for which no current-limit events have been detected; and adjusting the value of the compensation voltage to increase the duty cycle of the switching regulator in response to the detected time exceeding a time step threshold. ### Claim 2 (depends on 1) The method of claim 1, wherein the time step threshold is one of a fixed value and a variable value that is programmable. ### Claim 3 (depends on 2) The method of claim 2, wherein the time step threshold is a variable value that programmable to an integer number of switching cycles of the switching regulator. ### Claim 4 (depends on 1) The method of claim 1, wherein adjusting the value of the compensation voltage to increase the duty cycle comprises incrementing a value of the compensation voltage responsive to subsequent occurrences of the detected time exceeding the time step threshold. ### Claim 5 (depends on 4) The method of claim 4, wherein incrementing the value of the compensation voltage responsive to subsequent occurrences of the detected time exceeding the time step threshold comprises: detecting the occurrence of two consecutive occurrences of the detected time exceeding the time step threshold; and after detecting the occurrence of two consecutive occurrences of the detected time exceeding the time step threshold, incrementing the value of the compensation voltage responsive to the each subsequent occurrence of the detected time exceeding the time step threshold. ### Claim 6 (depends on 1) The method of claim 1 further comprising: incrementing a maximum inductor current count in response to the detection of each current-limit event; decrementing a value of the compensation voltage responsive to the maximum inductor current count reaching a threshold value; and resetting the maximum inductor current count responsive to the maximum inductor current count reaching the threshold value. ### Claim 7 (depends on 1) The method of claim 1, wherein detecting current-limit events comprises detecting whether a maximum current through an inductor of the switching regulator has been exceeded. ### Claim 8 (depends on 1) The method of claim 1 further comprising regulating an output voltage generated by the switching regulator based on the detecting current-limit events indicating a maximum current threshold has been exceeded, adjusting a value of a compensation voltage in response to the detected current-limit events, detecting a time for which no current-limit events have been detected, and adjusting the value of the compensation voltage to increase the duty cycle of the switching regulator. ### Claim 9 A switching regulator, comprising: a switching circuit configured to receive an input and including a switching element coupled to an electrical component, the switching element configured to control generation of an output based on a drive signal; a control circuit coupled to the switching circuit, the control circuit configured to detect signal-limit events indicating a maximum signal threshold has been exceeded in relation to a signal of the electrical component, and configured to adjust a value of a compensation signal in response to the detected signal-limit events, the compensation signal defining a duty cycle of the switching regulator and the control circuit further configured to detect a time for which no signal-limit events have been detected and to adjust the value of the compensation signal to increase the duty cycle of the switching regulator in response to the detected time exceeding a time step threshold; and a drive circuit coupled to the switching circuit and to the control circuit, the drive circuit configured to generate the drive signal based on the compensation signal. ### Claim 10 (depends on 9) The switching regulator of claim 9, wherein the electrical component in the switching circuit comprises an inductive element and the signal of the electrical component is a current through the inductive element. ### Claim 11 (depends on 10) The switching regulator of claim 10, wherein the switching circuit has a boost converter topology. ### Claim 12 (depends on 11) The switching regulator of claim 11, wherein the drive circuit comprises a comparator. ### Claim 13 (depends on 9) The switching regulator of claim 9, wherein the control circuit and the drive circuit are formed in the same integrated circuit. ### Claim 14 (depends on 9) The switching voltage regulator of claim 9, wherein the compensation signal is a compensation voltage and the signal of the electrical component is a current through the electrical component, and wherein the control circuit further comprises: a clamper circuit coupled to a compensation node on which the compensation voltage is provided, the clamper circuit configured to control a value of the compensation voltage responsive to an analog compensation control node voltage; a digital-to-analog converter coupled to the clamper circuit and configured to generate the analog compensation control voltage responsive to a compensation count; and maximum current control logic coupled to the digital-to-analog converter and configured to control the value of the compensation count responsive to current-limit events of the current through the electrical component being detected. ### Claim 15 (depends on 9) The switching regulator of claim 9, wherein each of the input and the output of the switching circuit is a voltage. ### Claim 16 A switching voltage regulator, comprising: a switching circuit configured to receive an input voltage and including a switching element coupled to an inductive element, the switching element configured to control generation of an output voltage in response to a drive signal; a control circuit coupled to the switching circuit, the control circuit configured to detect current-limit events indicating a maximum current threshold has been exceeded in relation to a current through the inductive element, and configured to adjust a value of a compensation voltage in response to the detected current-limit events, the compensation voltage defining a duty cycle of the switching voltage regulator and the control circuit further configured to detect a time for which no current-limit events have been detected and to adjust the value of the compensation voltage to increase the duty cycle of the switching voltage regulator in response to the detected time exceeding a time step threshold; and a drive circuit coupled to the switching circuit and to the control circuit, the drive circuit configured to generate the drive signal based on the compensation voltage. ### Claim 17 (depends on 16) The switching voltage regulator of claim 16, wherein the control circuit comprises: a clamper circuit coupled to a compensation node on which the compensation voltage is provided, the clamper circuit configured to control a value of the compensation voltage responsive to an analog compensation control node voltage; a digital-to-analog converter coupled to the clamper circuit and configured to generate the analog compensation control voltage responsive to a compensation count; and maximum current control logic coupled to the digital-to-analog converter and configured to control the value of the compensation count responsive to current-limit events being detected. ### Claim 18 (depends on 17) The switching voltage regulator of claim 17 further comprising an error amplifier having a first input configured to receive a feedback voltage derived from the output voltage and a second input configured to receive a reference voltage, the error amplifier having an output coupled to the compensation node and being configured to generate the compensation voltage when no current-limit events are detected in operation of the switching voltage regulator. ### Claim 19 (depends on 17) The switching voltage regulator of claim 17, wherein the maximum current control circuit is configured to adjust the value of the time step threshold based on one of a programmable time step threshold value and an integer number of switching cycles of the voltage regulator. ### Claim 20 (depends on 17) The switching voltage regulator of claim 17, wherein the maximum current control circuit is configured, responsive to detecting that the time for which no current-limit events have been detected exceeds the time step threshold, to increment a value of the compensation voltage responsive to subsequent occurrences of the time exceeding the time step threshold.