Micro-power-consumption low-voltage detection circuit for MCU

Abstract

The invention, which relates to the technical field of detection circuits, discloses a micro-power-consumption low-voltage detection circuit for an MCU, thereby realizing low-voltage detection duringpower-on and power-down processes of the M6CU. The micro-power-consumption low-voltage detection circuit comprises a mirror image current module; the input terminal of the mirror image current moduleis connected with an MCU power supply voltage and the output terminal of the mirror image current module is connected with the input terminal of a comparison module and one end of a ballast resistor;the input terminal of the comparison module is also connected to one end of the ballast resistor and the output terminal of the comparison module is connected to one end of the load and a shaping module; and the other ends of the ballast resistor and the load are grounded. The mirror image current module is used for generating one pair of mirror image currents changing with changes of the MCU power supply voltage; and the mirror image currents flow through the comparison module and the ballast resistor respectively. The comparison module is used for carrying out overturning outputting according to the voltage on the ballast resistor and the voltage change of the mirror image current module. The shaping module is used for shaping the overturning output from the comparison module and outputting corresponding high and low levels. The micro-power-consumption low-voltage detection circuit having advantages of compact structure and great convenience in controlling is convenient to popularizeand promote.

Description

technical field [0001] The invention relates to the technical field of detection circuits, in particular to a micro-power consumption low-voltage detection circuit for an MCU. Background technique [0002] Microprocessor MCU is a complex system, including ROM, SRAM, SFR, instruction operation unit and various peripherals. In order for the system to work stably and reliably, the power supply voltage VDD must be within a certain voltage range. When the voltage is too high, the circuit will be damaged, and when the voltage is too low, the transistors will not work properly, especially the ROM, and reading errors will occur. [0003] The operating voltage range can be determined by the user, but there is a process that the user cannot control, that is, the MCU must be powered on and off. During power-on and power-off, when VDD is less than a certain voltage, the MCU must stop working, especially in some dangerous operations, such as blasting. If there is a system execution err...

AI Technical Summary

Problems solved by technology

[0006] The invention provides a micro-power consumption low-voltage detection circuit for MCU, which solves the problems that the existing low-voltage detection circuit has relatively large operating current, large power consumption, and cannot meet the static power consumption requirements of the MCU.

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