PROTECTION CIRCUIT FOR CENTRAL PROCESSING UNIT

摘要

A protection circuit for a central processing unit (CPU) includes a power circuit, two comparators, a number of resistors, a thermistor, and an electronic switch. A non-inverting input terminal of the comparator is coupled to a first power terminal. An inverting input terminal of the comparator is connected to ground through the thermistor. An output terminal of the comparator is coupled to the electronic switch. When an operation temperature of the CPU exceeds a predefined temperature, the comparator enables the electronic switch to be turned on, to reduce an operation frequency of the CPU.

主权项

1. A protection circuit, comprising:
a central processing unit (CPU) comprising a heat protection pin, wherein when the heat protection pin is at a low-voltage level, an operation frequency of the CPU is reduced; a first resistor; a thermistor; a first electronic switch comprising a first, second, and third terminal; and a first comparator comprising an inverting input terminal, a non-inverting input terminal, and an output terminal; wherein the non-inverting input terminal of the first comparator is coupled to a first power terminal, the inverting terminal of the first comparator is connected to ground through the thermistor, and is coupled to a second power terminal through the first resistor; the output terminal of the first comparator is coupled to the first terminal of the first electronic switch; the second terminal of the first electronic switch is connected to ground, the third terminal of the first electronic switch is coupled to the heat protection pin of the CPU; when the first terminal of the first electric switch is at a high-voltage level, the second terminal of the first electronic switch is connected to the third terminal of the first electronic switch, when the first terminal of the first electronic switch is at a low-voltage level, the second terminal of the first electronic switch is disconnected from the third terminal of the first electronic switch; and wherein when the operation temperature of the CPU exceeds a first predefined temperature, the voltage of the inverting input terminal of the first comparator is greater than the voltage of the non-inverting input terminal of the first comparator, and the output terminal of the first comparator outputs a high-voltage level control signal to the first terminal of the first electronic switch.