# US 10,374,516 B2 · Non zero-voltage switching (ZVS) detection in resonant converters > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,374,516 B2 - Document ID: US10374516B2 - Status: Granted - Kind: B2 - Application number: 15/668,974 - Filed: 2017-08-04 - Published: 2018-02-22 - Granted: 2019-08-06 - Earliest claimed: 2016-08-19 - Assignees: Semiconductor Components Industries, LLC - Applicants: Fairchild Korea Semiconductor Ltd. - Inventors: Sangcheol Moon; Jintae Kim; Hangseok Choi - Web page: https://patentgrep.com/patent/US10374516B2 ## CPC - H02M 3/3376: {with automatic control of output voltage or current} - H02H 1/0007: {concerning the detecting means (in general G01R or other subclasses of G01; reed switches H01H71/2445)} - H02M 1/08: Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters - H02M 1/083: {for the ignition at the zero crossing of the voltage or the current} - H02M 1/32: Means for protecting converters other than automatic disconnection - H02M 1/36: Means for starting or stopping converters - H02M 3/01: {Resonant DC/DC converters} - H02M 3/33515: {with digital control} - H02M 3/33523: {with galvanic isolation between input and output of both the power stage and the feedback loop} - H02M 3/33546: {with automatic control of the output voltage or current (H02M3/33561 takes precedence)} - H02M 3/33571: {Half-bridge at primary side of an isolation transformer} - H02M 1/0009: {Devices or circuits for detecting current in a converter} - H02M 1/0035: {using burst mode control} - H02M 1/0054: {Transistor switching losses (periodically suspending operation of switching converter in low power mode H02M1/0035)} - 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) - H02H: EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS (indicating or signalling undesired working conditions G01R, e.g. G01R31/00, G08B; locating faults along lines G01R31/08; emergency protective devices H01H) - Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS ## Abstract According to an implementation, a resonant converter for detecting non-zero voltage switching includes an oscillator configured to generate a first clock signal to drive a first power switch, and a second clock signal to drive a second power switch. The resonant converter includes a non-zero voltage switching (non-ZVS) detection circuit configured to receive an integrated current sense signal sensed on a primary side of a transformer of a resonant network, and determine a polarity of a voltage of the integrated current sense signal at a predetermined point in the first clock signal or the second clock signal during a switching cycle. The non-ZVS detection circuit is configured to detect a non-ZVS event based on the polarity of the voltage of the integrated current sense signal at the predetermined point in the first clock signal or the second clock signal during the switching cycle. ## Claims ### Claim 1 A resonant converter for detecting non-zero voltage switching, the resonant converter comprising: an oscillator configured to generate a first clock signal to drive a first power switch, and a second clock signal to drive a second power switch, each of the first clock signal and the second clock signal being activated during a switching cycle; and a non-zero voltage switching (non-ZVS) detection circuit configured to receive an integrated current sense signal sensed on a primary side of a transformer of a resonant network, the non-ZVS detection circuit including a clock sensor configured to receive the first clock signal and sense a predetermined time point in the first clock signal, the predetermined time point being later than an activation time of the first clock signal and being before a deactivation time of the first clock signal, the non-ZVS detection circuit configured to determine a polarity of a voltage of the integrated current sense signal using the sensed predetermined time point, the non-ZVS detection circuit configured to detect a non-ZVS event based on the polarity of the voltage of the integrated current sense signal being negative or positive. ### Claim 2 (depends on 1) The resonant converter of claim 1, wherein the predetermined time point in the first clock signal is a halfway time point in the first clock signal. ### Claim 3 (depends on 1) The resonant converter of claim 1, wherein the non-ZVS detection circuit is configured to detect the non-ZVS event in response to the voltage of the integrated current sense signal being negative at the predetermined time point. ### Claim 4 (depends on 1) The resonant converter of claim 1, wherein the non-ZVS detection circuit is configured to detect the non-ZVS event in response to the voltage of the integrated current sense signal being positive at the predetermined time point. ### Claim 5 (depends on 1) The resonant converter of claim 1, wherein the clock sensor is configured to receive the first clock signal and sense a half-way time point in the first clock signal during the switching cycle, the resonant converter further comprising: a half-way point clock calculator configured to calculate a half-way time point in the second clock signal during the switching cycle based on the sensed half-way time point of the first clock signal, wherein the non-ZVS detection circuit is configured to determine the polarity of the voltage of the integrated current sense signal at the half-way time point in the second clock signal during the switching cycle using the integrated current sense signal and the calculated half-way time point of the second clock signal, wherein, in response to the polarity being negative, the non-ZVS detection circuit is configured to determine the non-ZVS event during the switching cycle. ### Claim 6 (depends on 1) The resonant converter of claim 1, wherein, in response to the detection of the non-ZVS event, the non-ZVS detection circuit is configured to trigger a protection circuit to increase a frequency or stop a switching operation of the oscillator. ### Claim 7 (depends on 1) The resonant converter of claim 1, wherein the switching cycle is a first switching cycle, and the non-ZVS detection circuit is configured to detect the non-ZVS event in a second switching cycle in response to the voltage of the integrated current sense signal during the second switching cycle being positive at the predetermined time point in the first clock signal. ### Claim 8 (depends on 7) The resonant converter of claim 7, wherein the sensor is configured to receive the first clock signal during the first switching cycle, and sense a half-way time point in the first clock signal during the first switching cycle, wherein the non-ZVS detection circuit is configured to determine the polarity of the voltage of the integrated current sense signal at the half-way time point in the first clock signal during the second switching cycle using the integrated current sense signal and the half-way time point of the first clock signal during the first switching cycle, wherein the non-ZVS detection circuit is configured to determine the non-ZVS event during the second switching cycle based on the polarity being positive. ### Claim 9 (depends on 1) The resonant converter of claim 1, further comprising: an integrated current sense circuit coupled to the resonant network on the primary side of the transformer, the integrated current sense circuit configured to generate the integrated current sense signal. ### Claim 10 (depends on 9) The resonant converter of claim 9, wherein the resonant network includes a resonant capacitor, a resonant inductor, and a magnetizing inductor, and the integrated current sense circuit includes a capacitor divider coupled to the resonant capacitor. ### Claim 11 A resonant converter for detecting non-zero voltage switching, the resonant converter comprising: an oscillator configured to generate a first clock signal to drive a first power switch, and a second clock signal to drive a second power switch, each of the first clock signal and the second clock signal being activated during a switching cycle; and a non-zero voltage switching (non-ZVS) detection circuit configured to receive an integrated current sense signal sensed on a primary side of a transformer of a resonant network, the non-ZVS detection circuit including a clock sensor configured to generate a sensor signal at a predetermined time point in the first clock signal, and a clock calculator configured to determine a predetermined time point in the second clock signal based on the sensor signal and the second clock signal, the non-ZVS detection circuit configured to determine a polarity of a voltage of the integrated current sense signal using the predetermined time point in the second clock signal, the predetermined time point being later than an activation time of the second clock signal and being before a deactivation time of the second clock signal, the non-ZVS detection circuit configured to detect a non-ZVS event in response to the polarity of the voltage of the integrated current sense signal being negative or positive at the predetermined time point in the second clock signal. ### Claim 12 (depends on 11) The resonant converter of claim 11, wherein the predetermined time point in the second clock signal is a halfway time point in the second clock signal during the switching cycle. ### Claim 13 (depends on 11) The resonant converter of claim 11, wherein the non-ZVS detection circuit is configured to detect a ZVS event in response to the polarity of the voltage of the integrated current sense signal being positive at the predetermined time point in the second clock signal. ### Claim 14 (depends on 11) The resonant converter of claim 11, wherein, in response to the detection of the non-ZVS event, the non-ZVS detection circuit is configured to trigger a protection circuit to increase a frequency or stop a switching operation of the oscillator. ### Claim 15 (depends on 11) The resonant converter of claim 11, wherein the resonant network includes a resonant capacitor, a resonant inductor, and a magnetizing inductor. ### Claim 16 A resonant converter for detecting non-zero voltage switching, the resonant converter comprising: an oscillator configured to generate a first clock signal to drive a first power switch, and a second clock signal to drive a second power switch, each of the first clock signal and the second clock signal being activated during a first switching cycle and a second switching cycle, the second switching cycle being after the first switching cycle; and a non-zero voltage switching (non-ZVS) detection circuit configured to receive an integrated current sense signal sensed on a primary side of a transformer of a resonant network, the non-ZVS detection circuit including a clock sensor configured to sense a predetermined time point in the first clock signal during the first switching cycle, the non-ZVS detection circuit configured to determine a polarity of a voltage of the integrated current sense signal using the predetermined time point in the first clock signal during the second switching cycle, the predetermined time point being later than an activation time of the first clock signal and being before a deactivation time of the first clock signal, the non-ZVS detection circuit configured to detect a non-ZVS event during the second switching cycle in response to the polarity of the voltage of the integrated current sense signal being positive at the predetermined time point in the first clock signal during the second switching cycle. ### Claim 17 (depends on 16) The resonant converter of claim 16, wherein the predetermined time point in the first clock signal is a halfway time in the first clock signal during the first switching cycle. ### Claim 18 (depends on 16) The resonant converter of claim 16, wherein the resonant network includes a resonant capacitor, a resonant inductor, and a magnetizing inductor.