US 12,132,385 B2
Control circuit, resonant converter and integrated circuit control chip
Chaojun Chen, Hangzhou (CN); Jian Deng, Hangzhou (CN); and Jin Jin, Hangzhou (CN)
Assigned to Silergy Semiconductor Technology (Hangzhou) LTD, Hangzhou (CN)
Filed by Silergy Semiconductor Technology (Hangzhou) LTD, Hangzhou (CN)
Filed on Jul. 20, 2022, as Appl. No. 17/868,954.
Claims priority of application No. 202110824240.3 (CN), filed on Jul. 21, 2021.
Prior Publication US 2023/0022357 A1, Jan. 26, 2023
Int. Cl. H02M 1/00 (2007.01); H02M 3/00 (2006.01)
CPC H02M 1/0019 (2021.05) [H02M 1/0025 (2021.05); H02M 1/0045 (2021.05); H02M 3/015 (2021.05)] 19 Claims
OG exemplary drawing
 
1. A control circuit for a resonant converter, the control circuit comprising:
a) a feedforward circuit configured to generate a feedforward current;
b) a charge feedback circuit configured to receive a resonant current sampling signal representing a resonant current of the resonant converter in a first mode to generate a charge feedback signal, and to receive the resonant current sampling signal and the feedforward current together to generate the charge feedback signal in a second mode;
c) a driving control circuit configured to generate driving signals according to the charge feedback signal and a first threshold signal, in order to control switching states of power transistors of the resonant converter, wherein the first threshold signal is generated according to an error compensation signal representing an error information between a feedback signal of an output signal of the resonant converter and a reference signal; and
d) wherein a change tendency of the feedforward current is opposite to a change tendency of the error compensation signal, such that a value of the feedforward current increases as the required output power decreases.