Overcurrent protection circuit
AssigneesHONG FU JIN PRECISION INDUSTRY (ShenZhen) CO., LTD., Hon Hai Precision Industry Co., Ltd.
InventorHAI-QING ZHOU
Life of this patent
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Abstract
An overcurrent protection circuit includes an operational amplifier, a first resistor, a second resistor, and a switch. A non-inverting input of the operational amplifier is connected to an output of a power supply circuit and an inverting input of the operational amplifier is connected to a first terminal of a load of the power supply circuit. A second terminal of the load is grounded. The first and second resistors are connected in parallel and coupled between the inverting input and the non-inverting input of the operational amplifier. The switch is coupled to an enable terminal of the power supply circuit and coupled to an output of the operational amplifier.
Claims4
An overcurrent protection circuit, comprising:
- an operational amplifier, wherein a non-inverting input of the operational amplifier is coupled to an output of a power supply circuit and an inverting input of the operational amplifier is connected to a first terminal of a load of the power supply circuit, a second terminal of the load is grounded;
- first and second resistors connected in parallel and coupled between the inverting input and the non-inverting input of the operational amplifier;
- and
- a switch coupled to an enable terminal of the power supply circuit and coupled to an output of the operational amplifier;
- wherein when current flowing through the second resistor is in an overcurrent state, the voltage across the first resistor is larger than an offset voltage of the operational amplifier, the output of the operational amplifier is at a high voltage level, the switch is turned on, the enable terminal of the power supply circuit is at a low voltage level, and the power supply circuit stops working.
Dependencies are inferred from the claim text.