# US 8,787,039 B2 · Hybrid adaptive power factor correction schemes for switching power converters > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,787,039 B2 - Document ID: US8787039B2 - Status: Granted - Kind: B2 - Application number: 13/552,567 - Filed: 2012-07-18 - Published: 2014-01-23 - Granted: 2014-07-22 - Earliest claimed: 2012-07-18 - Assignees: Dialog Semiconductor GmbH - Applicants: Fuqiang Shi; Xiaolin Gao; Hien Huu Bui; Yong Li; John William Kesterson - Inventors: Fuqiang Shi; Xiaolin Gao; Hien Huu Bui; Yong Li; John William Kesterson - Web page: https://patentgrep.com/patent/US8787039B2 ## CPC - H02M 1/4258: {using a single converter stage both for correction of AC input power factor and generation of a regulated and galvanically isolated DC output voltage (H02M1/4241 takes precedence)} - H02M 1/0003: {Details of control, feedback or regulation circuits} - 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) - Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS ## Abstract A method of a controller of a switching power converter that provides a configurable power factor control method for the switching power converter. The controller combines power regulation control methods of constant on-time control and constant power control to adjust the power factor of the switching power converter. The controller switches between constant on-time control and constant power control based on an input voltage of the power converter. ## Claims ### Claim 1 A switching power converter comprising: a transformer including a primary winding coupled to an input voltage and a secondary winding coupled to an output of the switching power converter; a switch coupled to the primary winding of the transformer, current through the primary winding being generated while the switch is turned on and not being generated while the switch is turned off; and a controller configured to generate a control signal to turn on or turn off the switch at each of a plurality of switching cycles of the switch; wherein the controller is further configured to generate the control signal to turn on the switch in a constant on-time mode of the switching power converter during each of the plurality of switching cycles for a first duration that is constant during each of the plurality of switching cycles corresponding to a first part of at least a single one of AC cycles of the input voltage responsive to the input voltage being less than a threshold voltage; and wherein the controller is further configured to generate the control signal to turn on the switch in a constant power mode of the switching power converter during each of the plurality of switching cycles for a second duration that varies during at least some of the plurality of switching cycles corresponding to a second part of said at least the single one of the AC cycles of the input voltage responsive to the input voltage being greater than the threshold voltage; wherein the controller does not receive a level of the input voltage and is further configured to determine whether the input voltage is less than or greater than the threshold voltage based on a slope of the current through the primary winding that is used by the controller as a proxy for the level of the input voltage. ### Claim 2 (depends on 1) The switching power converter of claim 1, wherein the controller is further configured to determine whether the input voltage is less than the threshold voltage or greater than the threshold voltage during at least some of the plurality of switching cycles of the switch of said at least the single one of the AC cycles. ### Claim 3 (depends on 1) The switching power converter of claim 1, wherein the second duration is less than the first duration. ### Claim 4 (depends on 1) The switching power converter of claim 1, wherein the controller is further configured to determine the first duration based on a percentage of time that the switch is turned on for the first duration within said at least the single one of the AC cycles of the input voltage to the switching power converter. ### Claim 5 (depends on 4) The switching power converter of claim 4, wherein the percentage of time that that the switch is turned on for the first duration within said at least the single one of the AC cycles of the input voltage to the switching power converter is indicative of a power factor of the switching power converter. ### Claim 6 (depends on 4) The switching power converter of claim 4, wherein the controller is configured to determine the first duration by: determining a configured percentage of time that the switch is turned on for the first duration corresponding to the first part of said at least the single of the AC cycles of the input voltage to the switching power converter; setting an initial duration of time that the switch is to be turned on during the constant on-time mode; calculating the percentage of time that the switch is turned on for the initial duration of time within said at least the single of the AC cycles of the input voltage to the switching power converter; and adjusting the initial duration of time until the configured percentage of time that the switch is turned on within said at least the single of the AC cycles of the input voltage to the switching power converter is reached. ### Claim 7 (depends on 1) The switching power converter of claim 1, wherein the controller is further configured to determine a third duration of time in which the switch is turned on during the constant on-time mode based on the output voltage during the constant on-time mode, wherein the third duration is greater than the first duration. ### Claim 8 (depends on 1) The switching power converter of claim 1, wherein the controller is configured to generate the control signal to turn on the switch in the constant power mode at a next switching cycle of said at least the single one of the AC cycles of the input voltage responsive to the input voltage being greater than the threshold voltage. ### Claim 9 In a controller, a method of controlling a switching power converter, the switching power converter including a transformer coupled between an input voltage and an output of the switching power converter, the transformer including a primary winding coupled to the input voltage and a secondary winding coupled to the output of the switching power converter, and a switch coupled to the primary winding of the transformer, current through the primary winding being generated while the switch is turned on and not being generated while the switch is turned off, the method comprising: generating a control signal to turn on or turn off the switch at each of a plurality of switching cycles of the switch; wherein the control signal is generated to turn on the switch in a constant on-time mode of the switching power converter during each of the plurality of switching cycles for a first duration that is constant during each of the plurality of switching cycles corresponding to a first part of at least a single one of AC cycles of the input voltage responsive to the input voltage being less than a threshold voltage; and wherein the control signal is generated to turn on the switch in a constant power mode of the switching power converter during each of the plurality of switching cycles for a second duration that varies during at least some of the plurality of switching cycles corresponding to a second part of said at least the single one of the AC cycles of the input voltage responsive to the input voltage being greater than the threshold voltage; wherein the control signal is generated to turn on the switch in either the constant on-time mode or the constant power mode using a slope of the current through the primary winding and without the controller receiving a level of the input voltage, the slope of the current being a proxy for the level of the input voltage. ### Claim 10 (depends on 9) The method of claim 9, further comprising: determining whether the input voltage is less than the threshold voltage or greater than the threshold voltage during at least some of the plurality of switching cycles of the switch of said at least the single one of the AC cycles. ### Claim 11 (depends on 9) The method of claim 9, wherein the second duration is less than the first duration. ### Claim 12 (depends on 9) The method of claim 9, further comprising: determining the first duration based on a percentage of time that the switch is turned on for the first duration within said at least the single one of the AC cycles of the input voltage to the switching power converter. ### Claim 13 (depends on 12) The method of claim 12, wherein the percentage of time that that the switch is turned on for the first duration within said at least the single one of the AC cycles of the input voltage to the switching power converter is indicative of a power factor of the switching power converter. ### Claim 14 (depends on 12) The method of claim 12, wherein determining the first duration comprises: determining a configured percentage of time that the switch is turned on for the first duration corresponding to the first part of said at least the single of the AC cycles of the input voltage to the switching power converter; setting an initial duration of time that the switch is turned on during the constant on-time mode; calculating the percentage of time that the switch is to be turned on for the initial duration of time within said at least the single of the AC cycles of the input voltage to the switching power converter; and adjusting the initial duration of time until the configured percentage of time that the switch is turned on within said at least the single of the AC cycles of the input voltage to the switching power converter is reached. ### Claim 15 (depends on 9) The method of claim 9, further comprising: determining a third duration of time in which the switch is turned on during the constant on-time mode based on the output voltage during the constant on-time mode, wherein the third duration is greater than the first duration. ### Claim 16 (depends on 9) The method of claim 9, further comprising: generating the control signal to turn on the switch in the constant power mode at a next switching cycle of said at least the single one of the AC cycles of the input voltage responsive to the input voltage being greater than the threshold voltage.