Chengdu Monolithic Power Systems Co., Ltd.

Shanglin Xu

Rui Wang

Lei Du

Haishi Wang

Zhenya Zhang

Yueying Du

A supply voltage generating circuit and method for a power system. The power system has a power input terminal to receive an input voltage, a system output terminal to provide a system voltage, a switching circuit, a bootstrap capacitor, and a first driver circuit with a power terminal. The switching circuit works in a buck mode to convert the input voltage to the system voltage, or in a boost mode to convert the system voltage to a boost output voltage. The bootstrap capacitor provides a bootstrap voltage at a bootstrap terminal. The method is generating an input pump voltage based on the input voltage and the boost output voltage, generating a first supply voltage based on the bootstrap voltage and the input pump voltage, and providing the first supply voltage to the power terminal of the first driver circuit.

Supply voltage generating method for a driver circuit in a power system

A charge pump comprises two bridge arms coupled in parallel, two capacitors, and a control circuit. Each bridge arm has two pairs of switches coupled in series, each pair of switches having two switches coupled in series through a common node. Each capacitor is connected between the two common nodes of the corresponding bridge arm. The control circuit provides a mode signal by comparing an output voltage of the charge pump with two threshold voltages via a hysteretic comparison, and provides two control signals with opposite logic states based on the mode signal to control each pair of the switches to work complementarily, wherein the logic states of the control signals flip in response to transiting from a first status to a second status of the mode signal, and maintain in response to transiting from the second status to the first status of the mode signal.

Charge pump with improved light-load efficiency and control method thereof

A control circuit used in a switch mode power supply is provided. The control circuit has an error amplifier, a first compensation network having a first resistance and a second compensation network having a second resistance. The error amplifier has a first input terminal, a second input terminal and an output terminal. The first compensation network is coupled between the first input terminal and the output terminal of the error amplifier. The second compensation network is coupled to the first input terminal of the error amplifier. When the switch mode power supply enters the transient state, the control circuit increases the first resistance of the first compensation network or decreases the second resistance of the second compensation network.

Switch mode power supply with improved transient performance and control circuit thereof

A driving circuit providing a driving signal at a driving terminal to drive a power switch. The driving signal has a first driving period and a second driving period. Both the first driving period and the second driving period have a first driving time interval. The driving circuit has a first equivalent on resistor established during the first driving time interval and located between a first voltage node and the driving terminal. The first equivalent on resistor has a first equivalent on resistance during the first driving time interval of the first driving period and has a second equivalent on resistance during the first driving time interval of the second driving period. The first equivalent on resistance and the second equivalent on resistance are not equal.

Growing community of inventors

Chengdu, China

Shanglin Xu