US 11,942,792 B2
Apparatus and methods for inverter mode switching in wireless charging transmitters
Wenhe Zhao, Singapore (SG); and Robin Tanzania, Singapore (SG)
Assigned to STMicroelectronics Asia Pacific PTE Ltd., Singapore (SG)
Filed by STMicroelectronics Asia Pacific Pte Ltd., Singapore (SG)
Filed on Nov. 30, 2020, as Appl. No. 17/107,161.
Prior Publication US 2022/0173617 A1, Jun. 2, 2022
Int. Cl. H02J 50/12 (2016.01); H02J 7/02 (2016.01); H02M 7/217 (2006.01); H02M 7/5387 (2007.01)
CPC H02J 50/12 (2016.02) [H02J 7/02 (2013.01); H02M 7/217 (2013.01); H02M 7/5387 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method for operating a wireless charging transmitter, the method comprising:
switching, by the wireless charging transmitter, an operating mode of a full bridge inverter of the wireless charging transmitter between a higher maximum transmitted power mode and a lower maximum transmitted power mode, wherein transmitted power of the wireless charging transmitter is controlled using an operating point comprising at least one of an alternating current (AC) frequency of the full bridge inverter, an AC duty cycle of the full bridge inverter, an AC phase shift of the full bridge inverter, or an input voltage of the wireless charging transmitter; and
changing, by the wireless charging transmitter, the operating point of the wireless charging transmitter between a higher induced voltage operating point and a lower induced voltage operating point to dampen a change in an induced rectifier voltage of a wireless charging receiver inductively coupled to the wireless charging transmitter while switching the operating mode between the higher maximum transmitted power mode and the lower maximum transmitted power mode by
reducing the AC frequency or increasing the AC duty cycle, the AC phase shift, or the input voltage to change the operating point to the higher induced voltage operating point while switching the operating mode from the higher maximum transmitted power mode to the lower maximum transmitted power mode and
increasing the AC frequency or reducing the AC duty cycle, the AC phase shift, or the input voltage to change the operating point to the lower induced voltage operating point while switching the operating mode from the lower maximum transmitted power mode to the higher maximum transmitted power mode.