A buck-boost converter comprises a first high-side switch and a first low-side switch connected in series between an input voltage terminal and ground, a second high-side switch and a second low-side switch connected in series between an output voltage terminal and ground, an inductor connected to a common node of the first high-side switch and the first low-side switch, and a common node of the second high-side switch and the second low-side switch and a control apparatus configured to generate gate drive signals, wherein the control apparatus comprises a first timer for setting a turn-off time of the first low-side switch, a second timer for setting a turn-off time of the second high-side switch and a peak current mode control device for setting a turn-off time of the first high-side switch and a turn-off time of the second low-side switch.