DC-DC converter
There is provided a DC-DC converter which is safe and secure, but yet with low power consumption. The DC-DC converter is configured to monitor the output voltage of an error amplifier, and detect that the output voltage of the error amplifier becomes a fixed value or smaller to drive an overheat protection circuit and a supply voltage monitoring circuit intermittently.
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 second end at which an output voltage is generated;
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; and
a protection circuit that outputs a signal to the output control circuit to turn off the switching element when detecting an abnormal state,
wherein the protection circuit operates intermittently only for a predetermined period of time in response to a signal based on the output signal of the error amplifier.
2. The DC-DC converter according to claim 1 , wherein the predetermined period is a period during which at least the switching element is on.
3. The DC-DC converter according to claim 1 , wherein the protection circuit comprises a supply voltage monitoring circuit that detects an abnormal state when the supply voltage is a predetermined voltage or lower.
4. The DC-DC converter according to claim 1 , wherein the protection circuit comprises an overheat protection circuit that detects an abnormal state when an ambient temperature is a predetermined temperature or higher.
5. 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 at which an output voltage is generated;
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;
a protection circuit that outputs a signal to the output control circuit to turn off the switching element when detecting an abnormal state,
wherein the protection circuit operates intermittently only for a predetermined period of time in response to a signal based on the output signal of the error amplifier; and
a comparator that outputs a control signal to cause the protection circuit to operate intermittently based on the output signal of the error amplifier.