# US 12,015,348 B2 · Control circuit for adaptive noise margin control for a constant on time converter > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,015,348 B2 - Document ID: US12015348B2 - Status: Granted - Kind: B2 - Application number: 17/892,154 - Filed: 2022-08-22 - Published: 2024-02-22 - Granted: 2024-06-18 - Earliest claimed: 2022-08-22 - Assignees: Elite Semiconductor Microelectronics Technology Inc. - Applicants: Elite Semiconductor Microelectronics Technology Inc. - Inventors: Yao-Ren Chang - Web page: https://patentgrep.com/patent/US12015348B2 ## CPC - H02M 3/158: including plural semiconductor devices as final control devices for a single load - H02M 1/0025: {Arrangements for modifying reference values, feedback values or error values in the control loop of a converter} - 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) ## Abstract A control circuit for adaptive noise margin control for a constant on time (COT) converter comprises an input reference terminal, amplifier, first switch device, voltage divider, trigger circuit, and output reference terminal. The amplifier has an input terminal coupled to the input reference terminal receiving a reference voltage signal. The first switch device has a control terminal coupled to an output of the amplifier, a first conduction terminal for receiving a voltage source signal, and a second conduction terminal. The voltage divider is coupled to the second conduction terminal and another input terminal of the amplifier. The trigger circuit, coupled to the voltage divider, is for triggering voltage change of a modified reference voltage signal selectively according to a high-side control signal of the COT converter. The output reference terminal coupled to the second conduction terminal outputs the modified reference voltage signal. ## Claims ### Claim 1 A control circuit for adaptive noise margin control for a constant on time (COT) converter, the control circuit comprising: an input reference terminal of the control circuit for receiving a reference voltage signal; an amplifier having a first input terminal coupled to the input reference terminal and having a second input terminal; a first switch device having a control terminal coupled to an output terminal of the amplifier, having a first conduction terminal for receiving a voltage source signal, and having a second conduction terminal; a voltage divider coupled to the second conduction terminal and the second input terminal; and a trigger circuit, coupled to the voltage divider, for triggering voltage change of a modified reference voltage signal selectively according to a high-side control signal for a high-side switch of the COT converter; and an output reference terminal of the control circuit coupled to the second conduction terminal and used for outputting the modified reference voltage signal based on the reference voltage signal, wherein the output reference terminal is used for being coupled to an input of a comparator of the COT converter. ### Claim 2 (depends on 1) The control circuit according to claim 1, wherein the trigger circuit comprises: a step resistor coupled to the voltage divider; and a second switch device coupled across the step resistor, wherein the second switch device turns on selectively according to the high-side control signal. ### Claim 3 (depends on 1) The control circuit according to claim 1, wherein the control circuit further comprises: a switching compensation circuit including: a compensation switch device coupled to the voltage divider, wherein the compensation switch device turns on selectively according to the high-side control signal; and a compensation current source coupled to the voltage divider through the compensation switch device selectively. ### Claim 4 (depends on 3) The control circuit according to claim 3, wherein the compensation current source is used for receiving the high-side control signal and outputting a variable current according to a measure of OFF period as a percentage of a total period for the high-side control signal. ### Claim 5 (depends on 4) The control circuit according to claim 4, wherein when the high-side control signal is asserted, the compensation switch device turns on such that the variable current output by the compensation current source flows into the voltage divider. ### Claim 6 (depends on 4) The control circuit according to claim 4, wherein the compensation current source comprises: a duty cycle estimation circuit for receiving the high-side control signal and generating a voltage signal indicating a duty cycle of the high-side control signal; a divider circuit coupled to the duty cycle estimation circuit and configured to output a scaled-down voltage signal according to the voltage signal; and a compensation controller coupled to the divider circuit and configured to output the variable current according to the scaled-down voltage signal. ### Claim 7 (depends on 6) The control circuit according to claim 6, wherein the duty cycle estimation circuit includes a low pass filter for receiving the high-side control signal and generating the voltage signal indicating the duty cycle of the high-side control signal. ### Claim 8 (depends on 6) The control circuit according to claim 6, wherein the compensation controller includes a voltage to current converter for outputting the variable current according to the scaled-down voltage signal. ### Claim 9 A control circuit for adaptive noise margin control for a constant on time (COT) converter, the control circuit comprising: an input reference terminal of the control circuit for receiving a reference voltage signal; an amplifier having a first input terminal coupled to the input reference terminal and having a second input terminal; a first switch device having a control terminal coupled to an output terminal of the amplifier, having a first conduction terminal for receiving a voltage source signal, and having a second conduction terminal; a voltage divider coupled to the second conduction terminal and the second input terminal; an output reference terminal of the control circuit coupled to the second conduction terminal through a current path and used for outputting a modified reference voltage signal based on the reference voltage signal; and a switching compensation circuit including: a plurality of compensation switch devices, wherein each of the plurality of compensation switch devices turns on selectively according to a corresponding compensation control signal based on a high-side control signal for a high-side switch of the COT converter; and a plurality of compensation current sources coupled to the current path through the plurality of compensation switch devices selectively. ### Claim 10 (depends on 9) The control circuit according to claim 9, wherein the control circuit further comprises: a trigger circuit including: a step resistor coupled to the voltage divider; and a second switch device coupled across the step resistor, wherein the second switch device turns on selectively according to the high-side control signal. ### Claim 11 (depends on 9) The control circuit according to claim 9, wherein the output reference terminal is used for being coupled to an input of a comparator of the COT converter. ### Claim 12 (depends on 9) The control circuit according to claim 9, wherein each of the plurality of compensation current sources is used for outputting a corresponding constant current. ### Claim 13 (depends on 9) The control circuit according to claim 9, wherein the control circuit further comprises a compensation resistor coupled between the second conduction terminal and the output reference terminal. ### Claim 14 (depends on 9) The control circuit according to claim 9, wherein when the corresponding compensation control signal is asserted, the corresponding compensation switch device turns on such that the corresponding current source sinks current from the current path. ### Claim 15 (depends on 9) The control circuit according to claim 9, wherein the control circuit further comprises: a duty cycle estimation circuit for receiving the high-side control signal and generating a voltage signal indicating a duty cycle of the high-side control signal; a divider circuit coupled to the duty cycle estimation circuit and configured to output a scaled-down voltage signal according to the voltage signal; and a compensation controller coupled to the divider circuit and configured to output the plurality of compensation control signals according to the scaled-down voltage signal. ### Claim 16 (depends on 15) The control circuit according to claim 15, wherein the duty cycle estimation circuit includes a low pass filter for receiving the high-side control signal and generating the voltage signal indicating the duty cycle of the high-side control signal. ### Claim 17 (depends on 15) The control circuit according to claim 15, wherein the compensation controller includes a plurality of comparators for output the plurality of compensation control signals according to the scaled-down voltage signal and respective compensation reference signals.