POWER SUPPLY DEVICE

摘要

The present invention relates to a power supply device for voltage converter, which includes a master switch, a first controller for generating a first pulse signal to drive the master switch to be turned on and turned off, a second controller for comparing a detection voltage representing an output voltage and/or load current with a first reference voltage to determine the logic state of a control signal generated by the second controller, and a coupling element connected between the first controller and the second controller for transmitting the logic state of the control signal to the first controller and enabling the first controller to determine the logic state of the first pulse signal according to the logic state of the control signal. The second controller includes a driving module for generating a second control signal to drive a synchronous switch to be turned on and turned off.

主权项

1. A power supply device for voltage conversion comprising:
a transformer comprising a primary winding and a secondary winding, a first end of the secondary winding directly connected to an output node; a master switch connected between an input voltage and a ground terminal; a synchronous switch connected between a second end of the secondary winding and a reference ground potential; a first controller generating a first pulse signal to turn the master switch on and off; a second controller comparing a detection voltage representing an output voltage and/or a load current with a first reference voltage, so as to determine a logic state of a control signal generated by the second controller according to the comparison result; and a coupling element connected between the first controller and the second controller transmitting the logic state of the control signal to the first controller, enabling the first controller to determine a logic state of the first pulse signal according to the logic state of the control signal; wherein the second controller comprises a driving module generating a second pulse signal; the driving module further detecting a voltage at a first common node of the secondary winding and the synchronous switch; when the first pulse signal turns off the master switch and the voltage at the first common node is dropped lower than a first threshold voltage, the second pulse signal is converted into a first logic state from a second logic state to turn on the synchronous switch, and when the voltage at the first common node is greater than a second threshold voltage, the second pulse signal is converted into the second logic state from the first logic state to turn off the synchronous switch.