US 9,812,970 B2
Systems and methods for constant current control with primary-side sensing and regulation in various operation modes
Lieyi Fang, Shanghai (CN); and Guo Wei Lin, Guangzhou (CN)
Assigned to Guangzhou On-Bright Electronics Co., Ltd., Guangzhou (CN)
Filed by GUANGZHOU ON-BRIGHT ELECTRONICS CO., LTD., Guangzhou (CN)
Filed on Feb. 25, 2016, as Appl. No. 15/54,032.
Application 15/054,032 is a division of application No. 14/536,514, filed on Nov. 7, 2014, granted, now 9,343,979.
Application 14/536,514 is a division of application No. 13/152,646, filed on Jun. 3, 2011, granted, now 8,917,527, issued on Dec. 23, 2014.
Prior Publication US 2016/0276939 A1, Sep. 22, 2016
Int. Cl. H02M 3/335 (2006.01); H02M 1/08 (2006.01); H02M 1/00 (2006.01)
CPC H02M 3/33507 (2013.01) [H02M 1/08 (2013.01); H02M 3/33515 (2013.01); H02M 2001/0009 (2013.01); Y02B 70/1433 (2013.01)] 25 Claims
OG exemplary drawing
 
1. A system for regulating a power converter, the system comprising:
a voltage-to-current-conversion component configured to generate a first current signal;
a current-signal generator configured to generate a second current signal;
a capacitor coupled to the current-signal generator and coupled, through a switch, to the voltage-to-current-conversion component, the capacitor being configured to generate a voltage signal;
a comparator configured to process information associated with the voltage signal and a sensed signal and generate a comparison signal based on at least information associated with the voltage signal and the sensed signal, the sensed signal being associated with a primary current flowing through a primary winding coupled to a secondary winding for a power converter;
a modulation-signal generator configured to receive at least the comparison signal and generate a modulation signal; and
a gate driver configured to receive the modulation signal and output a drive signal to a switch, the switch being configured to affect the primary current flowing through the primary winding;
wherein the voltage-to-current-conversion component is further configured to process information associated with the voltage signal and generate the first current signal based on at least information associated with the voltage signal;
wherein:
the drive signal is associated with at least one or more switching periods, each switching period of the one or more switching periods including at least an on-time period for the switch and a demagnetization period for a demagnetization process; and
the first current signal represents the primary current at the end of the on-time period;
wherein for each switching period of the one or more switching periods,
the first current signal discharges or charges the capacitor during only the demagnetization period;
the second current signal charges or discharges the capacitor during the switching period; and
the switching period multiplied by the second current signal is equal to the demagnetization period multiplied by the first current signal in magnitude.