US 2024/0186909 A1 · Soft Switch Control Circuit of Flyback Converter and Flyback Converter Applying the Same

Abstract

Disclosed is a soft switch control circuit and a flyback converter, comprising a primary edge part and a secondary edge part, and obtaining a trigger pulse signal according to a pre-turning on signal of a main switch transistor before the main switch transistor is turned on. The trigger pulse signal is transmitted to the secondary edge part by an isolation module to control the switch at a secondary edge circuit to conduct, to reduce source-drain voltage of the main switch circuit of the primary edge, to make the main switch transistor to turn on when the source-drain voltage is near zero voltage. The switch of the secondary edge circuit is a synchronous rectifying switch transistor or a discharge switch transistor connected at two ends of the synchronous rectifying switch transistor.

Claims26

Dependent claims

A soft switch control circuit of a flyback converter, the flyback converter comprising a primary edge part and a secondary edge part;

wherein the primary edge part comprises a main switch transistor, and the secondary edge part comprises a synchronous rectifying switch transistor,
wherein the soft switch control circuit comprises:
a switch control module, for controlling the main switch transistor to conduct at a first time period and the synchronous rectifying switch transistor to conduct at a second time period, and for controlling a switch transistor set at a secondary edge circuit to conduct at a third time period, the third time period being after the second time period and before the first time period,
wherein the switch control module comprises a primary edge control module, and the primary edge control module obtains a trigger pulse signal according to a pre-turning on signal of the main switch transistor, and the trigger pulse signal is transmitted to the secondary edge part by an isolation module, to control the switch transistor of the secondary edge circuit to conduct at the third time period.

1 more element

A soft switch control circuit of a flyback converter, the flyback converter comprising a primary edge part and a secondary edge part;

wherein the primary edge part comprises a main switch transistor, and the secondary edge part comprises a synchronous rectifying switch transistor,
wherein the soft switch control circuit comprises:
a switch control module, for controlling the main switch transistor to conduct at a first time period and the synchronous rectifying switch transistor to conduct at a second time period, and controlling a switch transistor set at a secondary edge circuit to conduct at a third time period, the third time period being after the second time period and before the first time period,
wherein the switch control module comprises a primary edge control module and a secondary edge control module, the primary edge control module generates a pre-turning on signal to control the main switch transistor to turn on, and the pre-turning on signal is transmitted to the secondary edge control module by an isolation module;
the secondary edge control module obtains a trigger pulse signal according to the pre-turning on signal of the main switch transistor, to control the switch transistor of the secondary edge circuit to conduct at the third time period.

2 more elements

A soft switch control circuit of a flyback converter, the flyback converter comprising a primary edge part and a secondary edge part, the primary edge part comprising a main switch transistor, the secondary edge part comprising a synchronous rectifying switch transistor, wherein the soft switch control circuit comprises:

a switch control module, for controlling the main switch transistor to conduct at a first time period and the synchronous rectifying switch transistor to conduct at a second time period, and controlling a switch transistor set at a secondary edge circuit to conduct at a third time period, the third time period being after the second time period and before the first time period,
wherein the switch control module comprises a primary edge control module, the primary edge control module obtains a driving signal to drive the switch transistor at the secondary edge circuit according to a pre-turning on signal of the main switch transistor, and the driving signal is transmitted to the secondary edge part by the isolation module to control the switch transistor of the secondary edge circuit to conduct at the third time period.

Dependencies are inferred from the claim text.

Soft Switch Control Circuit of Flyback Converter and Flyback Converter Applying the Same

Life of this patent

Soft Switch Control Circuit of Flyback Converter and Flyback Converter Applying the Same

Life of this patent

Abstract

Claims26