US 11,705,817 B2
LLC resonant converter with rectifiers processing partial load current
Dianbo Fu, San Jose, CA (US); Daocheng Huang, San Jose, CA (US); and Junjie Feng, San Jose, CA (US)
Assigned to Monolithic Power Systems, Inc., San Jose, CA (US)
Filed by Monolithic Power Systems, Inc., San Jose, CA (US)
Filed on Oct. 1, 2021, as Appl. No. 17/492,271.
Prior Publication US 2023/0105552 A1, Apr. 6, 2023
Int. Cl. H02M 3/335 (2006.01)
CPC H02M 3/33573 (2021.05) [H02M 3/33576 (2013.01)] 18 Claims
OG exemplary drawing
 
1. An LLC resonant converter comprising:
a switching full-bridge circuit comprising a first transistor, a second transistor, a third transistor and a fourth transistor with each transistor having a first end and a second end, the first ends of the first transistor and of the third transistor being connected to a DC input voltage, the second ends of the first transistor and of the third transistor being respectively connected to the first end of the second transistor and to the first end of the fourth transistor;
a transformer comprising a primary winding and a secondary winding with each winding having a first end and a second end, the first end of the secondary winding being connected to the second end of the fourth transistor and the second end of the secondary winding being connected to the second end of the second transistor;
a resonant circuit comprising a resonant capacitor, a resonant inductor, and a magnetizing inductance of the primary winding of the transformer, the resonant circuit being connected between a first switch node formed by the first and second transistors and a second switch node formed by the third and fourth transistors; and
a bridge rectifier that is connected between the first end and the second end of the secondary winding to generate a rectified output signal that is filtered to generate a DC output voltage at an output node.