Low-power consumption start-up and under-voltage protection circuit device

The utility model relates a low-power consumption start-up and under-voltage protection circuit device. The low-power consumption start-up and under-voltage protection circuit device comprises a start-up voltage detection module and a voltage hysteresis state latch, wherein the start-up voltage detection module is used for detecting power supply voltage of a chip; when the power supply voltage is higher than an upper limit voltage threshold, an enable end outputs enable signals, and the enable signals start a pulse-width modulation (PWM) control module of the chip to allow the chip to normally work; when the power supply voltage is lower than a lower limit voltage threshold, the enable signals close the PWM control module of the chip; and the voltage hysteresis state latch is used for realizing the function of under-voltage protection when the power supply voltage is lower than the lower limit voltage threshold and the enable signals close the PWM control module of the chip. According to the scheme, the power consumption of a start-up resistor of a power supply system of the PWM control module which is integrated with the circuit is reduced by integrating the sub-microampere start-up and under-voltage protection circuit in a switch power chip, the design difficulty of a low-standby power consumption power system is reduced, and the conversion efficiency of the power supply system is improved.