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.