US 11,929,667 B2
Switching converter and low-voltage startup circuit thereof
Jing Xu, Beijing (CN); Shoubao Yan, Beijing (CN); and Xiang Yu, Beijing (CN)
Assigned to SG MICRO CORP, Beijing (CN)
Appl. No. 17/763,744
Filed by SG MICRO CORP, Beijing (CN)
PCT Filed Sep. 4, 2020, PCT No. PCT/CN2020/113553
§ 371(c)(1), (2) Date Mar. 25, 2022,
PCT Pub. No. WO2021/057450, PCT Pub. Date Apr. 1, 2021.
Claims priority of application No. 201910910267.7 (CN), filed on Sep. 25, 2019.
Prior Publication US 2022/0345031 A1, Oct. 27, 2022
Int. Cl. H02M 3/156 (2006.01); H02M 1/36 (2007.01)
CPC H02M 1/36 (2013.01) [H02M 3/156 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A low-voltage startup circuit of a switching converter, wherein the switching converter comprises a main switching transistor, a synchronous switching transistor, an inductor and an output capacitor, and the low-voltage startup circuit comprises:
a comparator, configured to perform a comparison between an input voltage and a reference voltage and obtain a voltage detection signal according to a result of the comparison; and
a substrate voltage control module, configured to adjust a substrate voltage of the main switching transistor according to the voltage detection signal,
wherein when the voltage detection signal indicates that the input voltage is lower than/equal to the reference voltage, the substrate voltage control module is configured to increase the substrate voltage of the main switching transistor.