Patent ID: 9035640
Filing Date: 2015-05-19
Classification: H02M

Abstract:
1. A controller used in a buck-boost converter, wherein the buck-boost converter converting an input voltage into an output voltage comprises a first switch, a second switch, a third switch, a fourth switch and an inductor, the controller comprises: a clock generator configured to generate a periodical clock signal; an error amplifying circuit configured to generate a compensation signal based on a reference signal and a feedback signal representative of the output voltage; a comparing circuit coupled to the error amplifying circuit, wherein the comparing circuit is configured to compare a current sensing signal representative of the current flowing through the inductor with the compensation signal, and generate a reset signal; a proportional sampling circuit coupled to the clock generator and the error amplifying circuit, wherein based on the clock signal, the proportional sampling circuit samples the difference between the current sensing signal and the compensation signal, and generates a proportional sampling signal; a logic circuit coupled to the clock generator and the comparing circuit, wherein the logic circuit is configured to generate a logic control signal based on the clock signal and the reset signal; a pulse width increasing circuit coupled to the proportional sampling circuit and the logic circuit, wherein the pulse width increasing circuit is configured to generate a sum control signal based on the proportional sampling signal and the logic control signal, and wherein the pulse width increasing circuit increases the pulse width of the logic control signal by a modulation value to generate the pulse width of the sum control signal, and the modulation value is adjusted by the proportional sampling signal; a first driving circuit coupled to the pulse width increasing circuit, wherein based on the sum control signal, the first driving circuit generates a first driving signal and a second driving signal to respectively control the first switch and the second switch; and a second driving circuit coupled to the logic circuit, wherein based on the logic control signal, the second driving circuit generates a third driving signal and a fourth driving signal to respectively control the third switch and the fourth switch.