Chengdu Monolithic Power Systems Co., Ltd.

Monolithic Power Systems, Inc.

Hangzhou Mps Semiconductor Technology Ltd.

Siran Wang

Hui Li

Yuancheng Ren

Junming Zhang

Lei Miao

En Li

Guangzhuo Li

Yike Li

Lin Feng

Pengfei Liu

Kun Yi

Eric X Yang

Qiming Zhao

Yiqing Jin

Zilin Fan

Long Li

John Wiggenhorn

Jiangheng Lu

Hantao Lin

A switching mode power supply with improved power balance is discussed. It has a transformer, a primary circuit having a primary power switch coupled to a primary side of the transformer, and a plurality of secondary circuits coupled in parallel with each other at a secondary side of the transformer. A plurality of output voltages are provided at each of the secondary circuits; and each of the secondary circuits has a secondary power switch. If any of the output voltage deviates from a reference voltage, an ON time length of the corresponding secondary power switch is extended.

Switching mode power supply with improved power balance and the method thereof

A power supply control circuit for controlling a charging process of a power supply capacitor to produce a power supply voltage to power a power control chip is disclosed. The power supply control circuit has a charging switch controlled by a charging control signal, and the power supply capacitor is coupled to an input voltage when the charging switch is on. The power supply control circuit further has a charging control circuit, configured to provide the charging control signal to control the charging switch based on the input voltage, the power supply voltage and a voltage threshold. Thus a high turns ratio of an auxiliary winding to a secondary winding is not necessary, high voltage devices are not needed and the power dissipation caused by the high voltage is also reduced.

Voltage converter and a power supply control circuit thereof

A power system with adaptive minimum frequency is disclosed. The power system includes a resonant converter and a control circuit. Under the control of the control circuit, the resonant converter works with an adaptive minimum frequency. The value of the adaptive minimum frequency is preset and is selected by an equivalent resistance or an output voltage of the resonant converter.

Power system with adaptive minimum frequency

An over-current protection circuit has a current sensing circuit, an over-current comparing circuit, an isolation circuit and a control circuit. The current sensing circuit generates a current sensing signal based on a current flowing through an inductor of a voltage converter. The over-current comparing circuit receives the current sensing signal and generates a first over-current indication signal based on the current sensing signal. The isolation circuit receives the first over-current indication signal and generates a second over-current indication signal based on the first over-current indication signal. The control circuit receives the second over-current indication signal, and generates a control signal to control a switch of the voltage converter. The control circuit turns off the switch when the second over-current indication signal indicates that an over-current condition occurs.

Voltage converter with over-current protection and over-current protection method thereof

An isolated switching regulator with adjustable power supplies is discussed. The isolated switching regulator includes a control circuit having a loop controller and a driver, which are powered by different power source based on different output voltage conditions.

Isolated switching regulators with smart power supply and the method thereof

A method to control a synchronous rectifier (SR) switch in a switching power supply circuit having an energy storage component coupled to the SR switch, the method is: generating a turning-ON control signal by comparing a drain-source sensing voltage of the SR switch with a turn ON threshold voltage; limiting an ON-time of the SR switch at least not less than a minimum on-time when the turning-ON control signal is asserted and an indicium signal having a first level indicating a fast mode; and removing the minimum on-time limitation to the SR switch and turning OFF the SR switch responsive to the drain-source sensing voltage of the SR switch exceeding a turn OFF threshold voltage when the turning-ON control signal is asserted and the indicium signal having a second level indicating a slow mode.

Switching power supply circuit and associated control circuit with false turn-on prevention of synchronous rectifier switch

A totem pole PFC (Power Factor Correction) circuit, having: a first switch, a second switch and a control circuit. When the totem pole PFC circuit works in CCM (Continuous Current Mode), the control circuit is configured to turn on a main switch when a current detecting signal indicative of an AC input current of the totem pole PFC circuit decreases to a current valley reference signal, and keep the main switch ON for a first on-time period. When the totem pole PFC circuit works in DCM (Discontinuous Current Mode), the control circuit is configured to turn on the main switch at a valley of a switching voltage after expiry of a time delay started from when the AC input current decreases to zero, and keep the main switch ON for a second on-time period.

Control circuit for a totem pole power factor correction circuit and the method thereof

A method for controlling a switching mode power supply is disclosed. An auxiliary winding feedback voltage of the switching mode power supply is sampled and held to obtain an auxiliary winding sample hold voltage. The auxiliary winding feedback voltage is sampled and held at an inflection point time to obtain an auxiliary winding inflection point voltage when the switching mode power supply operates in DCM or CRM. A secondary rectifier forward voltage signal is generated based on the auxiliary winding sample hold voltage and the auxiliary winding inflection point voltage before the switching mode power supply operates in CCM. A correction voltage is provided based on the secondary rectifier forward voltage signal when the switching power supply operates in CCM. An error amplifier signal is generated based on the correction voltage. The output power of the switching mode power supply is adjusted based on the error amplifier signal.

Control circuit of switching mode power supply and control method thereof

A controller of an isolated switching converter having a primary and secondary switch, the controller includes a valley detection circuit for providing a valley pulse signal in response to valleys of a resonant voltage, a pulse frequency modulation circuit for providing a pulse frequency modulation signal based on a feedback signal indicative of an output voltage, a primary on enable circuit for providing a primary on enable signal based on the pulse frequency modulation signal and valley pulse signal, a secondary logic circuit for generating a secondary control signal to control the secondary switch based on a primary off detection signal, a zero cross detection signal and the primary on enable signal, and a primary logic circuit for generating a primary control signal to control the primary switch based on a synchronous signal electrically isolated from the primary on enable signal.

Isolated switching converter with secondary side modulation and control method thereof

A controller of a switching converter includes an error amplifying circuit, a first comparison circuit, a valley detection circuit, a valley selection circuit and a frequency control circuit. The error amplifying circuit generates a compensation signal based on the difference between a reference signal and a feedback signal. The first comparison circuit compares the compensation signal with a modulation signal and generates a pulse frequency modulation signal. The valley detection circuit detects valleys of a resonant voltage of the switching converter and generates a valley pulse signal. The valley selection circuit generates a valley enable signal corresponding to a target valley number based on the pulse frequency modulation signal and the valley pulse signal. The frequency control circuit generates a frequency control signal to control the switching frequency of the first switch based on the valley enable signal and the valley pulse signal.

Switching converter with quasi-resonant control and control method thereof

A control circuit and control method for an interleaved switching converter having a first and second interleaved voltage regulating circuit. The control method is: controlling a first switch of the first voltage regulating circuit operating in quasi-resonant mode, turning ON a second switch of the second voltage regulating circuit after the first switch is turned ON for a half switching period, generating a current sensing signal by detecting a current flowing through the second switch, generating a peak signal, wherein the peak signal is adjusted when a voltage across the second switch is higher than a voltage reference at the time the second switch is turned ON, and turning OFF the second switch when the current sensing signal increases to the peak signal.

Interleaved switching converter with quasi-resonant control and control method thereof

A multi-converter switching power supply includes a first switching converter with a first output capacitor, a second switching converter with a second output capacitor, a bypass switch coupled across the second output capacitor, and a bypass control circuit for controlling the bypass switch. Input terminals of the first and switching converters are coupled in parallel, while output terminals of the first and switching converters are coupled in series to provide a total output voltage to a load. When detecting that the second output voltage approaches a negative voltage, the bypass control circuit turns on the bypass switch, so as to protect the second output capacitor from being damaged by a reverse DC voltage.

Input-parallel output-series multi-converter switching power supply

An isolated switching converter has a primary switch and a control circuit. The control circuit has a first sampling circuit, a second sampling circuit, a compensation circuit and a feedback control circuit. The first sampling circuit is coupled to an auxiliary winding of a transformer to receive a voltage on the auxiliary winding and is configured to generate a first feedback signal having an alternating current signal indicative of an output voltage. The second sampling circuit is coupled to the auxiliary winding through a first rectifier and is configured to generate a second feedback signal having a direct current signal indicative of the output voltage. The compensation circuit is configured to generate a compensation signal based on the first feedback signal, the second feedback signal and a reference threshold. The feedback control circuit is configured to generate a primary control signal of the primary switch based on the compensation signal.

Isolated switching converter with high feedback accuracy and control method

A control circuit of a zero current controlled dimming circuit having a high side power switch, a low side power switch and an inductor, having: an error circuit, providing a compensation signal based on a reference signal and a current sense signal indicative of an output current; a compensation circuit, providing a compensation off time signal based on the compensation signal and a peak value sample and hold signal indicative of a peak value of an inductor current; and a control signal generating circuit, providing a low side switch control signal to control the low side power switch based on the compensation off time signal, wherein after the inductor current decreases to zero, the low side power switch maintains on for a compensation off time period determined by the compensation off time signal.

Zero current controlled dimming circuit and a method thereof

A power converter includes a first and a second transformers having different auxiliary winding voltage levels. A bias voltage supply circuit generates a bias supply voltage of an integrated circuit used to control the power converter, and includes a first and a second bias supply branches jointly coupled to a supply capacitor to provide the bias supply voltage. When the bias supply voltage is higher than a threshold voltage, the first bias supply branch to receive the one with lower level of the two auxiliary winding voltages is switched from a deactivation state to an activation state to provide the bias supply voltage, when the bias supply voltage is less than the threshold voltage, the second bias supply branch to receive the one with larger level of the two auxiliary winding voltages is switched from the deactivation state to the activation state to provide the bias supply voltage.

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Hangzhou, China

Siran Wang