STARTING CIRCUIT OF ERROR AMPLIFIER AND DC-DC CONVERTER HAVING CIRCUIT

摘要

PROBLEM TO BE SOLVED: To provide a starting circuit of an error amplifier, capable of rapidly stepping up an output voltage of the error amplifier to put it into an operation state in starting, in the error amplifier designed so that the output voltage of the error amplifier in an initial state is lower than the lower limit of the amplitude of an oscillation signal into a comparator input in a stopping state.;SOLUTION: At the time of stoppage of the error amplifier, a switch control circuit controls switches 27, 29 and 30 so that they are simultaneously closed, and discharges the electric charges accumulated in a phase adjusting capacity 24 to put them in an initial state. At the time of starting of the same, the switch control circuit controls the switches so that only the switch 30 is opened and the switches 27, 29 are closed, and thus, the phase adjusting capacity 24 is rapidly charged by a charging circuit 31 via a short circuit 32. When the output voltage of the error amplifier reaches the lower limit value of a control range of a triangular wave amplitude and a time ratio signal is outputted from the output section of the comparator, the switch control circuit opens the switches 27, 29 to put them in a usual state.;COPYRIGHT: (C)2009,JPO&INPIT