DC-DC converter including an intermittent overcurrent protection circuit
View Patent ↗There is provided a DC-DC converter which is safe and secure, but yet with low power consumption. The DC-DC converter is configured such that an overcurrent protection circuit is operated intermittently only for a predetermined period of time based on a signal output from an output control circuit to turn on a switching element.
1. A DC-DC converter, comprising:
a switching element connected between a first end of an inductor and an input terminal of the DC-DC converter, the inductor having a second end connected to an output terminal;
an error amplifier that monitors the output voltage;
an output control circuit that outputs a control signal to a gate of the switching element based on an output signal of the error amplifier to establish a switching cycle;
an overcurrent protection circuit that includes a comparator driven by a switch-connected bias circuit and that outputs a first signal to the output control circuit when current flowing through the switching element is a predetermined current or higher to turn off the switching element; and
a timer circuit configured to operate for a set counting period when the switching element is on and to output a second signal to the overcurrent protection circuit,
wherein the second signal is based on the control signal of the output control circuit and controls the switch-connected bias circuit, such that the overcurrent protection circuit operates intermittently and only for a predetermined period of time during the counting period.
2. The DC-DC converter according to claim 1 , wherein the timer circuit outputs a third signal to cause the overcurrent protection circuit to operate intermittently based on the control signal of the output control circuit.