Silergy Semiconductor Technology (hangzhou) Ltd

Shaobin Zhang

Yongjiang Bai

Zhiliang Hu

Le Li

Qiukai Huang

Jin Jin

Jinping Dong

A control circuit for driving a power switch in a switching power supply can include: a start-up transistor having a drain coupled to a drain of the power switch, and a source coupled to a drain voltage detecting circuit; a gate voltage detecting circuit configured to detect a gate voltage of the power switch, to compare the gate voltage against a first threshold voltage, and to change an on drive current and an off drive current in response thereto; and the drain voltage detecting circuit being configured to detect a drain voltage of the power switch, to compare the drain voltage against a second threshold voltage, and to change the on drive current and the off drive current in response thereto.

Control method and control circuit for switch in switching power supply

A method of controlling an isolated converter can include: (i) sampling and holding an output voltage of the isolated converter during a present switching cycle to generate a reference voltage signal that is proportional to the output voltage; (ii) comparing, in a predetermined time interval before a next switching cycle, the output voltage against the reference voltage signal, and activating a wake-up signal when the output voltage is less than the reference voltage signal, in order to control a voltage at a secondary winding to represent a variation of the output voltage; (iii) detecting a voltage of the primary winding or the secondary winding, and generating a voltage detection signal; and (iv) controlling the power switch according to the voltage detection signal, in order to maintain the output voltage as an expected voltage.

Control method and control circuit for improving dynamic response of switching power supply

A power supply circuit for a switching power supply including a power switch configured to receive a DC input voltage, can include: a switching control circuit configured to receive a charge voltage signal of a charge capacitor, a reference voltage signal, and a PWM control signal, and to generate a switching control signal; a control unit having a supply voltage from the charge capacitor, where the charge capacitor includes a first terminal coupled to the switching control circuit, and a second terminal coupled to ground; and where when the switching power supply is in a start-up phase, the power switch is turned on, the first switch is turned off, and the DC input voltage charge the charges capacitor through the power switch, and the control unit begins operating when the charge voltage signal reaches a level of starting voltage of the control unit.

Power supply circuit and power supply method for switching power supply

A voltage sampling control circuit can include: a bleeder circuit that generates a sampling signal by sampling a voltage across a winding of a transformer of an isolated switching power supply; a blanking time signal control circuit that activates a first blanking time signal when the sampling signal is higher than a first reference voltage, and activates a second blanking time signal when the sampling signal rises to a level of a second reference voltage, where active portions of the first and second blanking time signals overlap, and the sampling signal is not detected during activation of either of the first and second blanking time signals; a converter configured to convert the sampling signal to a detection signal after both of the first and second blanking time signals have been deactivated; and a sample and hold circuit configured to receive the detection signal, and to generate a feedback signal.

Voltage sampling control method and related control circuit for isolated switching power supply

Controlling an isolated converter can include: controlling a first voltage signal across the secondary winding according to a wake-up signal to reflect change of an output voltage of the isolated converter; obtaining a second voltage signal representing the first voltage signal at the primary side; controlling the main power switch according to a detection result of the second voltage signal; generating the wake-up signal according to the output voltage and a first threshold voltage when the isolated converter is in a dynamic loading state of a normal operating mode; generating the wake-up signal according to the output voltage and a second threshold voltage when the isolated converter is in a load steady state of a standby operating mode; and generating the wake-up signal according to the output voltage and a third threshold voltage when the isolated converter is in a dynamic loading state of the standby operating mode.

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Hangzhou, China

Shaobin Zhang