US Patent No. 10,194,497

CONTROL CIRCUIT, CONTROL METHOD AND SWITCHING POWER SUPPLY THEREOF


Patent No. 10,194,497
Issue Date January 29, 2019
Title Control Circuit, Control Method And Switching Power Supply Thereof
Inventorship Xiaoping Chen, Hangzhou (CN)
Assignee Silergy Semiconductor Technology (Hangzhou) LTD, Hangzhou (CN)

Claim of US Patent No. 10,194,497

1. A control circuit for generating a switching control signal to control switching operations of a power switch in a power stage circuit, the control circuit comprising:a) a first control loop configured to receive a first voltage feedback signal, and to generate a first compensation signal;
b) a voltage regulating circuit configured to receive an output voltage signal of said power stage circuit, and to generate a second compensation signal according to a difference between said output voltage signal of said power stage circuit during first and second operating time periods, wherein a dimming signal is active during said first operating time period, and said dimming signal is inactive during said second operating time period;
c) said voltage regulating circuit being configured to generate a voltage maintenance signal according to said output voltage signal of said power stage circuit throughout said first operating time period, and to generate said second compensation signal by utilizing said voltage maintenance signal during said second operating time period; and
d) a control and driving circuit configured to receive said first and second compensation signals and a first sense voltage signal that represents a current through an inductor of said power stage circuit, and to generate an OFF signal by comparing said first compensation signal against said first sense voltage signal during said first operating time period and comparing said second compensation signal against said first sense voltage signal during said second operating time period, and said switching control signal according to said OFF signal and an ON signal.