# US 10,312,811 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 10,312,811 B2 - Document ID: US10312811B2 - Status: Granted - Kind: B2 - Application number: 16/179,325 - Filed: 2018-11-02 - Published: 2019-03-07 - Granted: 2019-06-04 - 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/US10312811B2 ## 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 detects current-limit events indicating a maximum current threshold of a switching converter has been reached, A compensation voltage is adjusted in response to the detected current-limit events, where the compensation voltage defines a duty cycle of the switching converter. A time for which no current-limit events have been detected is sensed, and the value of the compensation voltage adjusted in response to the detected time reaching a time step threshold. ## Claims ### Claim 1 A control circuit configured to control switching circuitry of a switching converter and to detect current-limit events indicating a maximum current threshold of an inductive element of the switching circuitry has been reached, the control circuit configured to adjust a value of a compensation voltage in response to the detected current-limit events, wherein the compensation voltage defines a duty cycle of the switching converter and the control circuit further is 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 converter in response to the detected time reaching a time step threshold. ### Claim 2 (depends on 1) The control circuit of claim 1, wherein the control circuit is further configured to generate a current limit pulse signal in response to each detected current-limit event. ### Claim 3 (depends on 1) The control circuit of claim 1 further comprising a compensation node on which the compensation voltage is provided and a compensation network coupled between the compensation node and a reference node and configured to filter the compensation voltage. ### Claim 4 (depends on 3) The control circuit of claim 3, wherein the compensation network comprises a series-connected resistive element and capacitive element. ### Claim 5 (depends on 1) The control circuit of claim 1, wherein the time step threshold is one of a fixed value and a variable value that is programmable. ### Claim 6 (depends on 5) The control circuit of claim 5, wherein the time step threshold is a variable value that programmable to an integer number of switching cycles of the switching converter. ### Claim 7 (depends on 1) The control circuit of claim 1, wherein the control circuit is further configured to increment a value of the compensation voltage responsive to the detected time reaching the time step threshold. ### Claim 8 (depends on 7) The control circuit of claim 7, wherein the control circuit is configured to: detect the occurrence of two consecutive occurrences of the detected time reaching the time step threshold; and after the occurrence of two consecutive occurrences of the detected time reaching the time step threshold is detected, to increment the value of the compensation voltage responsive to the each subsequent occurrence of the detected time reaching the time step threshold. ### Claim 9 (depends on 1) The control circuit of claim 1, wherein the control circuit is further configured to: increment a maximum inductive element current count in response to the detection of each current-limit event; decrement a value of the compensation voltage responsive to the maximum inductive element current count reaching a threshold value; and reset the maximum inductive element current count responsive to the maximum inductive element current count reaching the threshold value. ### Claim 10 A switching voltage regulator, comprising: switching circuitry including an input node configured to receive an input voltage and including a switching element coupled to an inductive element, the switching circuitry configured to control switching of the switching element responsive to a drive signal to generate an output voltage on an output node; and a control circuit configured to detect current-limit events indicating a current through the inductive element has reached a maximum inductor current threshold, and configured to generate the drive signal based on a compensation voltage to control a duty cycle of the switching voltage regulator and an inductor current supplied on the output node to eliminate the occurrence of current-limit events, the current control circuit further configured to detect whether a time for which no current-limit events have been detected reaches a time step threshold and to control the compensation voltage to increase the duty cycle responsive to the time reaching the time step threshold. ### Claim 11 (depends on 10) The switching voltage regulator of claim 10, wherein the switching circuitry has a buck converter topology. ### Claim 12 (depends on 10) The switching voltage regulator of claim 10, wherein the switching circuitry has a buck boost converter topology. ### Claim 13 (depends on 10) The switching voltage regulator of claim 10 further comprising an output capacitor coupled to the output node of the switching circuitry. ### Claim 14 (depends on 10) The switching voltage regulator of claim 10, wherein the drive signal is a pulse width modulated signal. ### Claim 15 (depends on 10) The switching voltage regulator of claim 10, wherein the control circuit further comprises: an RS latch having a set input configured to receive a clock signal, a reset input, and an output coupled to the switching element to provide the drive signal to the switching element; a PWM comparator having a first input configured to receive the compensation voltage, a second input configured to receive a current control signal, and an output coupled to the reset input of the RS latch; and a slope compensation circuit having an input configured to receive the clock signal and an output coupled to the second input of the PWM comparator, the slope compensation circuit configured to generate a slope compensation signal responsive to the clock signal to adjust a value of the current control signal. ### Claim 16 A method, comprising: detecting current-limit events indicating a maximum current threshold of a switching converter has been reached; 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 converter; detecting a time for which no current-limit events have been detected; and adjusting the value of the compensation voltage in response to the detected time reaching a time step threshold. ### Claim 17 (depends on 16) The method of claim 16, wherein adjusting the value of the compensation voltage comprises adjusting the value of the compensation voltage to increase the duty cycle of the switching converter, and wherein the time step threshold is one of a fixed value and a programmable value. ### Claim 18 (depends on 17) The method of claim 17, wherein the time step threshold is a programmable value that is set to an integer number of switching cycles of the switching converter. ### Claim 19 (depends on 16) The method of claim 16, wherein adjusting the value of the compensation voltage comprises incrementing a value of the compensation voltage responsive to subsequent occurrences of the detected time reaching the time step threshold. ### Claim 20 (depends on 19) The method of claim 19, wherein incrementing the value of the compensation voltage responsive to subsequent occurrences of the detected time reaching the time step threshold comprises: detecting the occurrence of two consecutive occurrences of the detected time reaching the time step threshold; and after detecting the occurrence of two consecutive occurrences of the detected time reaching the time step threshold, incrementing the value of the compensation voltage responsive to the each subsequent occurrence of the detected time reaching the time step threshold.