CURRENT MODE CONTROL TYPE SWITCHING POWER SUPPLY DEVICE

摘要

A switching power supply device includes a first switch, a second switch, a current sensing portion configured to sense current flowing in the second switch, and a controller configured to control the first and second switches. The controller controls the first switch and the second switch in accordance with current sensed by the current sensing portion if a ratio of the output voltage to the input voltage is a predetermined value or lower, and controls the first switch and the second switch independently of the current sensed by the current sensing portion if the ratio of the output voltage to the input voltage is higher than the predetermined value.

主权项

1. A current mode control type switching power supply device comprising:
a first switch having a first terminal connected to a first application terminal to which an input voltage is applied; a second switch having a first terminal connected to a second terminal of the first switch and a second terminal connected to a second application terminal to which a predetermined voltage lower than the input voltage is applied; a current sensing portion configured to sense current flowing in the second switch; and a controller configured to control the first switch and the second switch, wherein if a ratio of an output voltage to the input voltage is a predetermined value or lower, the controller controls the first switch and the second switch in accordance with the current sensed by the current sensing portion, and if the ratio of the output voltage to the input voltage is higher than the predetermined value, the controller controls the first switch and the second switch independently of the current sensed by the current sensing portion.