Monolithic Power Systems, Inc.

Chengdu Monolithic Power Systems Co., Ltd.

Joulwatt Technology (hangzhou) Co., Ltd.

Zhejiang University

Aisin Aw Co., Ltd.

Michigan State University

Silergy Semiconductor Technology (hangzhou) Ltd

Joulwatt Technology Co., Ltd.

Junming Zhang

Yuancheng Ren

Lei Du

En Li

Siran Wang

Naixing Kuang

Kaiwei Yao

Eric X Yang

Pitleong Wong

Jin Hu

Xunwei Zhou

James Copland Moyer

Yang Shi

Lei Miao

Yunping Lang

Huanyu Lu

Zhaoqi Mao

Wei P Chen

Yike Li

Yiqing Jin

Guoqiang Liu

Bairen Liu

Kun Yi

Chen Zhao

Hui Li

Bin Liu

Zhiqian Chen

Fang Zheng Peng

Xiangyong Xu

Sicong Lin

Jiali Cai

Hao Long

Xianghua Jiang

Shuai Shao

Zhen Zhang

Xiaopeng Dong

Zhijun Ye

Yuanchang Ren

Yuxin Li

Bai Lang

Yucen Li

Zhi Gao

Jianjia Zhang

Kuang Sheng

Miao Lei

Disclosed is a high-efficiency flyback converter and a control method thereof. The flyback converter comprises: a transformer; a first switch transistor and a second switch transistor; a resonant capacitor; a control circuit, for controlling the second switch transistor to be turned on for a first time before the first switch transistor is turned on during a switching cycle, controlling the second switch transistor to maintain turn-off state during a first time stage, to control energy transmission between primary and secondary sides to include two time stages during a switching cycle, the first time stage lasts for a set time period during a freewheeling process. The present disclosure allows the main switch transistor to realize zero-voltage turn-on, thus reducing conduction loss of the primary and the secondary sides, reducing ripples of an output voltage and a current of the secondary side, and being beneficial to improving operating efficiency.

Flyback converter with high efficiency and control method thereof

A switching mode power supply with zero voltage switching is discussed. It adopts a first secondary signal generator and a second secondary signal generator to control a secondary switch circuit to be turned on once again after a current freewheeling process is over.

Switching mode power supply with zero voltage switching and the method thereof

A bridge circuit with series-connected switches and associated control method. The bridge circuit has a first bridge arm and a second bridge arm coupled to a common node, the first bridge arm has a plurality of series-connected first main switches, each first main switch is coupled in parallel with an auxiliary module, each first auxiliary module has a clamping capacitor and an auxiliary switch, the first bridge arm receives a first main switch signal to control the plurality of series-connected first main switches, the second bridge arm receives a second main switch signal, the control method is sensing voltages of the clamping capacitors in the first bridge arm, correspondingly generating voltage sensing signals, and turning on at least one auxiliary switch for a predetermined time during a dead time according to a sorting result of the voltage sensing signals.

Bridge circuit with series-connected switches and control method thereof

A protection circuit and an illumination driving circuit are described herein. The protection circuit comprises a detection circuit, detecting a current flowing through a first switch to obtain a current detection signal and determining whether there is leakage at an input terminal according to the current detection signal; a control circuit, controlling the first switch to switch on intermittently, detecting the current flowing through the first switch by the detection circuit during a switch-on period of the first switch, and keeping the load at a disconnection state if the detection circuit determines there is leakage; and the first switch, connected to the input terminal, and a control terminal of the first switch being connected to the control circuit, and the first switch being controlled by the control circuit to be switched on intermittently. The present invention has the protection function and enhances safety during load removing and installation processes.

Protection circuit and illumination driving circuit

The present invention provides a synchronous rectification control circuit, a method and a flyback switching circuit. A drive circuit outputs a drive signal to control the turn-on and turn-off of a synchronous rectification transistor; a threshold comparison circuit controls the drive circuit to output a pull-up drive signal to turn on the synchronous rectification transistor when a drain-source voltage is lower than a preset low threshold voltage and controls the drive circuit to output a pull-down drive signal to turn off the synchronous rectification transistor when the drain-source voltage is higher than or equal to a preset high threshold voltage; a voltage regulation control circuit controls the drive circuit to output a drive signal for pulling up a voltage of the drive signal to a preset pull-up voltage high value when the drain-source voltage is lower than a preset voltage regulation reference value.

Synchronous rectification control circuit, method and flyback switch circuit

The present invention discloses a bleeder circuit; solutions of the present invention may be applied in linear driving and switch driving solutions; a threshold voltage is a zero crossing value, and when the input voltage is zero crossing, the load current at this time is zero; a bleeder current is generated to make the input current greater than a holding current of a TRIAC dimmer, to maintain turning-on of the TRIAC dimmer, and a second time is set as a delay time, which reduces power consumption. In the application of switch driving solution, the current regulating circuit is controlled to be enabled according to the waveform features of the previous and latter halves of periods of the sine wave as well as the size of the input current of the driving circuit. The present invention reduces bleeder current, improves system efficiency and system reliability while ensuring the dimming performance; meanwhile, it is good for enlarging the maximum turning-on angle of TRIAC, and satisfies the requirement for maximum output current more easily.

Bleeder circuit

A control circuit for a power converter can include: a current detection circuit configured to generate a current detection signal that represents an input current; a control signal generator configured to generate a switching control signal such that the current detection signal is directly proportional to a voltage conversion function; and a power stage circuit of the power converter being controlled by the switching control signal, where the voltage conversion function is a ratio of an input voltage and an output voltage of the power converter.

Control circuit and control method for a power converter

An isolated switching mode power supply, having: an input terminal; an output terminal; a transformer having a primary winding and a secondary winding; a primary power switch coupled to the primary winding; a secondary power switch coupled between the secondary winding and the output terminal of the power supply; a secondary controller configured to generate a frequency modulation signal based on the output voltage and the first feedback signal; a coupled device configured to provide a frequency control signal based on the output voltage and the frequency modulation signal; and a primary controller configured to provide a switching signal to control the primary power switch based on the current sense signal and the frequency control signal.

Isolated switching mode power supply and the method thereof

A peak sample circuit for AC voltage, including: a rectifier coupled to receive an AC voltage and to rectify the AC voltage to generate a rectified signal; a delay circuit coupled to receive the rectified signal and to delay the rectified signal to generate a delayed rectified signal; a comparison circuit coupled to receive the delayed rectified signal and to generate a square signal based on the comparison of the rectified signal and the delayed rectified signal; and a sample output circuit coupled to receive the rectified signal, wherein the sample output circuit samples the rectified signal under the control of the square signal and provides a peak sample signal representative of the peak value of the AC voltage.

Peak sample circuit for AC voltage and method thereof

A PFC circuit includes: a switching circuit having a power switch; an on time control circuit for controlling an on time period of the power switch; a first off time control circuit; a second off time control circuit; and a logic circuit selectively controls the power switch working under CCM or DCM; when working under CCM, the first off time control circuit controls an off time period of the power switch and when working under DCM, the second off time control circuit controls the off time period of the power switch.

Multi-mode PFC control and control method thereof

An improved gate drive circuit is provided for a power device, such as a transistor. The gate driver circuit may include: a current control circuit; a first secondary current source that is used to control the switching transient during turn off of the power transistor and a second secondary current source that is used to control the switching transient during turn on of the power transistor. In operation, the current control circuit operates, during turn on of the power transistor, to source a gate drive current to a control node of the power transistor and, during turn off of the power transistor, to sink a gate drive current from the control node of the power transistor. The first and second secondary current sources adjust the gate drive current to control the voltage or current rate of change and thereby the overshoot during the switching transient.

High efficiency gate drive circuit for power transistors

An isolated switching converter includes a transformer having a primary winding, a secondary winding and an auxiliary winding, a primary switch coupled to the primary winding, a secondary switch coupled to the secondary winding, and a feedback circuit coupled to the auxiliary winding to generate a feedback signal indicative of the output voltage. Under normal operation, the primary switch is controlled based on the feedback signal and the secondary switch is controlled based on the status of the primary switch. Under light load condition, the secondary switch is controlled based on the output voltage. The secondary switch is turned on to generate a negative secondary current flowing through the secondary winding and turned off when the negative secondary current reaches a secondary current threshold. The primary switch is turned on based on a negative primary current and turned off when the primary current reaches a primary current threshold.

Flyback converter with current controlled low power mode

A switch mode power supply having an output terminal configured to provide an output voltage, the switch mode power supply has a first switch and a control circuit. The control circuit is configured to provide a switching control signal to control the first switch. The control circuit is configured to provide the switching control signal based on a first pulse signal having a first frequency and a second frequency for a light load condition, and the control circuit is configured to provide the switching control signal based on a second pulse signal for a non-light load condition.

Switch mode power supply, control circuit and associated control method

An AC signal detector having: a rectify circuit having a first input terminal and a second input terminal configured to receive an AC signal, and an output terminal configured to provide a rectified signal based on the AC signal; a detecting circuit having an input terminal coupled to the output terminal of the rectify circuit to receive the rectified signal, and an output terminal configured to provide a square signal based on the rectified signal; and an unplug indicate circuit having an input terminal coupled to the detecting circuit to receive the square signal, and an output terminal configured to provide an unplug indicate signal based on the square signal.

AC signal detector and the method thereof

A switching mode power supply, having: an input port; an output port; an energy storage component and a pair of power switches coupled between input port and the output port; an error amplifier configured to generate an amplified error signal based on the feedback signal and the reference signal; an error comparator configured to generate a frequency control signal based on the amplified error signal and the first sawtooth signal; a peak current generator configured to generate a peak current signal based on the frequency control signal; a peak current comparator configured to generate a current limit signal based on the peak current signal and the current sense signal; and a logic circuit configured to generate a switching signal to control the power switches based on the frequency control signal and the current limit signal.

Switching mode power supply and the method thereof

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Hangzhou, China

Junming Zhang