The utility model discloses a
control circuit in a DCDC converter, belongs to the technical field of electronic circuits, and solves the problem of generating a
control signal to a BUCK type DC-
DC voltage stabilizer. Comprising a VOUT selection circuit module, and the VOUT selection circuit module receives output
voltage of the
BUCK converter and outputs a reference
voltage value after
processing the output
voltage; the charging circuit module is used for timing after receiving the charging current and the
square wave signal, and outputting a charging voltage value within the timing time; and two input ends of the
comparator module are respectively coupled with the VOUT selection circuit module and the charging circuit module. According to the utility model, the output voltage of the
BUCK converter can be output after being processed through the VOUT selection circuit module to serve as a reference voltage value of the
comparator, the charging circuit module is used for timing and enables the
comparator module to generate a
control signal TON, and an upper power tube is kept to be opened within the timing, so that the
BUCK converter is charged. And the
control signal TON is output and is connected to a post-stage
logic control circuit to regulate and control the working state of the power tube.