US 12,438,470 B2
Peak efficiency tracking in an LLC converter of a multi-stage power conversion system
Ranajay Mallik, Ghaziabad (IN); and Akshat Jain, Nahan (IN)
Assigned to STMicroelectronics International N.V., Geneva (CH)
Filed by STMicroelectronics International N.V., Geneva (CH)
Filed on Aug. 9, 2023, as Appl. No. 18/232,185.
Prior Publication US 2025/0055376 A1, Feb. 13, 2025
Int. Cl. H02M 3/335 (2006.01); H02M 1/00 (2006.01); H02M 3/00 (2006.01); H02M 7/48 (2007.01)
CPC H02M 3/33573 (2021.05) [H02M 1/0058 (2021.05); H02M 3/01 (2021.05); H02M 3/33571 (2021.05); H02M 7/4815 (2021.05)] 20 Claims
OG exemplary drawing
 
1. An LLC resonant converter, comprising:
a switching bridge having a plurality of power switches, the switching bridge configured to receive a DC voltage input and generate a square waveform based on a pulse-modulated frequency (PFM) signal at the switching bridge; and
a resonant tank circuit coupled to the switching bridge and comprising a resonant inductor, wherein the resonant tank circuit is excited in response to receiving the square waveform, and wherein the PFM signal is adjusted such that an elapsed time between a rising edge of a Drain-Source Voltage of a power switch and a zero-crossing point of current flowing through the resonant inductor falls within a predetermined range corresponding to the resonant tank circuit operating at its resonant frequency.