Patent ID: 11880217
Assignee: CHENGDU MONOLITHIC POWER SYSTEMS CO., LTD.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC G  H | IPC G  H

Claim 12:
13. A method of operating a power management circuit having a first pin, a second pin, a third pin, a fourth pin, a first switch coupled between the second pin and the third pin, a second switch coupled between the third pin and the fourth pin, an external inductor coupled between the third pin and a rechargeable battery, wherein the method comprising:
selecting a minimum value among a plurality of feedback control signals as a feedback control signal;
providing a first current sensing signal by sensing a current flowing through the inductor;
providing a second current sensing signal by adding a DC offset voltage on to the first current sensing signal;
comparing the selected feedback control signal with the second current sensing signal and providing a first comparison signal;
generating a constant time control signal with a constant time based on the first comparison signal;
providing a first control signal and a second control signal based on the first comparison signal and the constant time control signal; and
configuring the first switch and the second switch to operate in a buck mode or a boost mode, respectively controlling the OFF-time of the first switch and the ON-time of the second switch to be the constant time.