Overcurrent protection circuit
Disclosed herein is an overcurrent protection circuit configured to, upon detection of an output current that flows through a switch element reaching a first overcurrent limit value, reduce an overcurrent limit value for the output current from the first overcurrent limit value to a second overcurrent limit value smaller than the first overcurrent limit value.
1. An overcurrent protection circuit, comprising:
an overcurrent detection section configured to detect whether an output current that flows through a switch element is reaching a first overcurrent limit value; and
a hiccup control section configured to start a hiccup driving operation on the switch element based on a result of the detection by the overcurrent detection section, wherein
the hiccup driving operation includes control of a drive signal for the switch element such that a predetermined ON period and a predetermined OFF period of the switch element are periodically repeated to reduce an overcurrent limit value for the output current from the first overcurrent limit value to a second overcurrent limit value which is smaller than the first overcurrent limit value.
2. The overcurrent protection circuit according to claim 1 , wherein the overcurrent detection section is further configured to reduce a rate of rise of the output current from a first rate of rise to a second rate of rise which is lower than the first rate of rise, based on the detection of the output current reaching the first overcurrent limit value and a transition of the switch element to an ON state.
3. The overcurrent protection circuit according to claim 1 , wherein the drive signal for the switch element is controlled based on a result of comparing the output current with the first overcurrent limit value.
4. A switch device, comprising:
a switch element; and
an overcurrent protection circuit configured to monitor an output current that flows through the switch element, wherein
the overcurrent protection circuit comprises:
an overcurrent detection section configured to detect whether the output current that flows through the switch element is reaching a first overcurrent limit value; and
a hiccup control section configured to start a hiccup driving operation on the switch element based on a result of the detection by the overcurrent detection section, wherein
the hiccup driving operation includes control of a drive signal for the switch element such that a predetermined ON period and a predetermined OFF period of the switch element are periodically repeated to reduce an overcurrent limit value for the output current from the first overcurrent limit value to a second overcurrent limit value which is smaller than the first overcurrent limit value.
5. An electronic device, comprising:
a switch device; and
a load connected to the switch device, wherein the switch device comprises:
a switch element; and
an overcurrent protection circuit configured to monitor an output current that flows through the switch element, wherein the overcurrent protection circuit comprises:
an overcurrent detection section configured to detect whether the output current that flows through the switch element is reaching a first overcurrent limit value; and
a hiccup control section configured to start a hiccup driving operation on the switch element based on a result of the detection by the overcurrent detection section, wherein
the hiccup driving operation includes control of a drive signal for the switch element such that a predetermined ON period and a predetermined OFF period of the switch element are periodically repeated to reduce an overcurrent limit value for the output current from the first overcurrent limit value to a second overcurrent limit value which is smaller than the first overcurrent limit value.
6. The electronic device according to claim 5 , wherein the load is one of a valve lamp, a relay coil, a solenoid, a light-emitting diode, and a motor.
7. A vehicle, comprising:
an electronic device comprising,
a switch device; and
a load connected to the switch device, wherein the switch device comprises:
a switch element; and
an overcurrent protection circuit configured to monitor an output current that flows through the switch element, wherein the overcurrent protection circuit comprises:
an overcurrent detection section configured to detect whether the output current that flows through the switch element is reaching a first overcurrent limit value; and
a hiccup control section configured to start a hiccup driving operation on the switch element based on a result of the detection by the overcurrent detection section, wherein
the hiccup driving operation includes control of a drive signal for the switch element such that a predetermined ON period and a predetermined OFF period of the switch element are periodically repeated to reduce an overcurrent limit value for the output current from the first overcurrent limit value to a second overcurrent limit value which is smaller than the first overcurrent limit value.