US 11,682,973 B2
Advanced constant off-time control for four-switch buck-boost converter
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 Jul. 16, 2021, as Appl. No. 17/378,111.
Application 17/378,111 is a continuation of application No. 16/747,781, filed on Jan. 21, 2020, granted, now 11,121,632.
Application 16/747,781 is a continuation of application No. 16/273,297, filed on Feb. 12, 2019, granted, now 10,651,722, issued on May 12, 2020.
Application 16/273,297 is a continuation in part of application No. 16/000,757, filed on Jun. 5, 2018, granted, now 10,250,142, issued on Apr. 2, 2019.
Claims priority of provisional application 62/649,328, filed on Mar. 28, 2018.
Prior Publication US 2021/0359605 A1, Nov. 18, 2021
Int. Cl. H02M 3/158 (2006.01); H02M 3/157 (2006.01); H02M 1/088 (2006.01)
CPC H02M 3/1582 (2013.01) [H02M 1/088 (2013.01); H02M 3/157 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An apparatus comprising:
a first timer configured to determine a turn-off time of a first high-side switch of a buck-boost converter, wherein a turn-off time of the first high-side switch is a time period from a turn-off time instant of the first high-side switch to an immediately subsequent turn-on time instant of the first high-side switch; and
a second timer configured to determine a turn-off time of a second low-side switch of the buck-boost converter based on a comparison between a first signal and a second signal, the first signal being equal to a first predetermined constant times an input voltage of the buck-boost converter, and the second signal being generated based on a signal equal to a second predetermined constant times an output voltage of the buck-boost converter, wherein a turn-off time of the second low-side switch is a time period from a turn-off time instant of the second low-side switch to an immediately subsequent turn-on time instant of the second low-side switch.