| 摘要 |
PROBLEM TO BE SOLVED: To provide a power conversion device having a reactor, a main switch and a synchronous rectification switch capable of controlling a current critical mode without detecting reactor currents.SOLUTION: A power conversion device 1 includes: FET11 and 12; a rector 15; and a control circuit 17. The control circuit 17 detects a switching transition time as a time since FET 12 is instructed to be turned off until the source/drain voltage of the FET 11 is turned into a threshold voltage Vth, and controls the FET 11 and 12 on the basis of the switching transition time. There is a predetermined relation between the switching transition time and reactor currents IL so that it is possible to grasp the reactor currents IL in accordance with the switching transition time. Therefore, it is possible to control the power conversion device 1 in a current critical mode without detecting the reactor currents. |
