US 11,705,811 B2
Buck-boost converter and hybrid control method
Bo Yang, Allen, TX (US); Xiaoyu Xi, Dallas, TX (US); and David Meng, Los Altos, CA (US)
Assigned to M3 Technology Inc., Taipei (TW)
Filed by M3 Technology Inc., Taipei (TW)
Filed on Nov. 10, 2020, as Appl. No. 17/94,184.
Prior Publication US 2022/0149737 A1, May 12, 2022
Int. Cl. H02M 3/158 (2006.01); H02M 1/08 (2006.01); H02M 1/00 (2006.01)
CPC H02M 3/1582 (2013.01) [H02M 1/08 (2013.01); H02M 1/0009 (2021.05)] 18 Claims
OG exemplary drawing
 
1. An apparatus comprising:
a buck converter portion of a buck-boost converter configured to operate under a constant on-time control scheme, wherein an on-time of a high-side switch of the buck converter portion is determined by a buck on-time timer, wherein the buck on-time timer is configured to determine a turn-off edge of a gate drive signal applied to the high-side switch of the buck converter portion of the buck-boost converter, wherein a comparator of the buck on-time timer comprises a first input configured to receive a first ramp, and a second input configured to receive a first threshold voltage, and wherein the first ramp is generated by a first current source having a current level proportional to an input voltage of the buck-boost converter, and the first threshold voltage is proportional to an output voltage of the buck-boost converter; and
a boost converter portion of the buck-boost converter configured to operate under a constant off-time control scheme, wherein an off-time of a low-side switch of the boost converter portion is determined by a boost off-time timer.