Current controller and protection circuit

摘要

A current controller for generating a control signal which controls supply current flowing from a power source to a load includes an interface circuit which sets a threshold based on an instruction from an outside of the current controller, a threshold setting circuit which stores and outputs the threshold, a sensing circuit which determines a current or a temperature of a sensing element, and outputs a signal indicating that the supply current should be interrupted as the control signal if a determined current or a determined temperature exceeds the threshold, and a sensing control circuit which generates a clock signal including pulses with a predetermined period. The sensing circuit determines the current or the temperature of the sensing element during an active period of the clock signal.

主权项

1. A current controller for generating a control signal which controls supply current flowing from a power source to a load, comprising:
an interface circuit which sets a current threshold and a temperature threshold based on an instruction from an outside of the current controller; a current threshold setting circuit which stores and outputs the current threshold; a temperature threshold setting circuit which stores and outputs the temperature threshold; a clock generating circuit which generates a clock signal; a current sensing circuit which determines a current of a current sensing element during a period of the clock signal, and to output a current control signal indicating that the supply current should be controlled so as to prevent an over current flowing if a determined current exceeds the current threshold; and a temperature sensing circuit which determines a temperature of a temperature sensing element during a period of the clock signal, and to output a temperature control signal indicating that the supply current should be controlled so as to avoid overheating if a determined temperature exceeds the temperature threshold, wherein the period of the clock signal decreases when the supply current increases.