SWITCH CONTROL CIRCUIT AND CONTROL METHOD FOR A FOUR-SWITCH BUCK-BOOST CONVERTER

摘要

An apparatus can include: (i) a power stage circuit including first, second, third, and fourth switches and an inductor; (ii) a constant time control circuit configured to generate a switch trigger signal according to switching signals of the first and third switches; (iii) a PWM control circuit configured to receive an input voltage signal via the input terminal, an output voltage via the output terminal, and the switch trigger signal, and to generate switching signals to control the first, second, third, and fourth switches; and (iv) the PWM control circuit being configured to turn on or off the first and third switches in response to the switch trigger signal being activated.

主权项

1. An apparatus, comprising:
a) a power stage circuit comprising a first switch, an inductor, and a fourth switch coupled in series between input and output terminals, a second switch having a first terminal coupled to a common node of said first switch and said inductor, and a second terminal coupled to ground, a third switch having a first terminal coupled to a common node of said fourth switch and said inductor, and a second terminal coupled to ground; b) a constant time control circuit configured to generate a switch trigger signal according to switching signals of said first and third switches; c) a pulse-width modulation (PWM) control circuit configured to receive an input voltage signal via said input terminal, an output voltage via said output terminal, and said switch trigger signal, and to generate switching signals to control said first, second, third, and fourth switches; and d) said PWM control circuit being configured to turn on or off said first and third switches in response to said switch trigger signal being activated.