Chengdu Monolithic Power Systems Co., Ltd.

Pengfei Liu

Siran Wang

Guangzhuo Li

Hao Wang

Chuanhao Xu

A power factor control circuit for controlling a PFC circuit is disclosed. The PFC circuit is controlled to operate in one or more operation mode(s) (e.g., CCM, BCM, and DCM) in a single cycle of an input rectified voltage based on a load condition of the PFC circuit. The power factor control circuit includes a control reference circuit and a switching control circuit. The control reference circuit provides a peak current signal, a valley current signal and a turn-on delay signal based on a first current reference, a second current reference, and an input average current. The switching control circuit provides a switching control signal to control a dominant power switch of the PFC circuit based on a current sense signal, the peak current signal, the valley current signal, and the turn-on delay signal.

Multi-mode PFC circuit and control method thereof

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

A method for controlling a voltage converter includes the following steps. A feedback compensation signal is generated based on an output voltage of the voltage converter. An output representation signal is compared with a first threshold and a second threshold. A switch control signal to control the turn-on and turn-off of a power circuit of the voltage converter is adjusted based on an ultra-light load feedback value when the output representation signal is less than the first power threshold. The switch control signal is adjusted based on the feedback compensation signal when the output representation signal is greater than the first power threshold. The second threshold is greater than the first threshold, and the ultra-light load feedback value is greater than the feedback compensation signal when the output representation signal is equal to the second threshold.

Circuits and method for reducing light load power dissipation of a voltage converter

A power chip with a switching converter, having: a power pin configured to receive an input voltage, an indicating signal generating circuit configured to generate an indicating signal; a communicating circuit configured to receive/transmit communication data; and a multi-function pin configured to receive/transmit communication data and/or to provide the indicating signal under certain conditions.

Power chip with a multi-function pin

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 controller used in a resonant converter having a switching circuit and a resonant tank. The switching circuit has a high side switch and a low side switch. The controller has a feedback processing circuit for providing a reference signal based on a feedback signal. The reference signal changes at a first slope based on the feedback signal when the feedback signal is higher than a first voltage threshold, and the reference signal changes at a second slope based on the feedback signal when the feedback signal is lower than the first voltage threshold. The turning off of the high side switch is controlled by a high side off signal, which is generated based on the reference signal and a voltage sampling signal indicative a voltage across a resonant capacitor of the resonant tank.

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Hangzhou, China

Pengfei Liu