Surge suppression power supply protection circuit

Abstract

The present invention discloses a surge suppression power supply protection circuit. The circuit comprises a power supply reverse connection prevention circuit, a low-voltage turn-off circuit and a high-voltage suppression circuit. The power supply reverse connection prevention circuit can prevent the reverse connection of the power supply, when the input voltage surge exceeds a set output voltage, the output voltage can still maintain the set output voltage to protect a post-stage circuit. A window voltage range value through which a power supply voltage passes is set through the low-voltageturn-off circuit and the high-voltage suppression circuit, the voltage in the set window range can pass, the circuit output is 0 when the voltage is lower than a lower limit value, and the output voltage is a set upper limit voltage when the voltage is higher than an upper limit value. Compared with an existing power supply protection integrated circuit, the working voltage of the circuit does notneed to be obtained from an input power supply, the influence on the input power supply is small, the circuit belongs to a micro-power-consumption circuit, after a rear-stage DC / DC stops working, theshunting effect of the whole circuit on the input power supply is very small, and a vehicle-mounted battery can be protected when the circuit is applied to an automobile.

Description

technical field [0001] The invention relates to a surge suppression power protection circuit. Background technique [0002] The automobile generates a lot of electromagnetic interference due to the operation of the ignition system, generator and rectifier system. These interferences have a wide frequency band and spread to the power supply system through conduction, coupling or radiation, thereby affecting the normal operation of electronic equipment. This kind of electrical stress threat is mainly summarized as the content defined by the ISO 7637-2 and ISO 10605 standards. For various threats generated on the circuit, how to achieve effective protection without affecting the driving power supply requires some protection on the power supply side of the circuit measure. There are two commonly used methods, the first is direct shutdown, and the second is voltage suppression. Direct shutdown is the most effective and direct way to protect the back-end equipment. The direct sh...

AI Technical Summary

Problems solved by technology

This scheme has a strong protection mechanism, but the circuit is complicated and the cost is high, which is unbearable for low-cost applications, such as GPS positioning, driving recorder, etc. At the same time, the circuit in this mode needs to obtain energy from the input power supply to generate the energy required for the operation of the integrated circuit. working voltage, there is energy loss to the input power

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