Protection circuit for detecting source power supply voltages through single-chip microcomputer, and control method

Abstract

The invention provides a protection circuit for detecting source power supply voltages through a single-chip microcomputer, and a control method. The protection circuit is composed of a voltage sampling circuit and a single-chip microcomputer control circuit. The protection circuit is different from a conventional pure hardware circuit in terms of overvoltage and undervoltage protection modes, realizes protection by performing logic computation by use of one single-chip microcomputer, and also guarantees high precision and high accuracy while reducing components; under the condition that hardware circuit parameters are not changed, protection functions of different voltages points can be realized by adjusting values through software, a digital, general and standard mode of a power converter is realized, and the research and development and production efficiency is improved; and at the same time, through other ports of the single-chip microcomputer, such functions of the power converter as overheat protection, overcurrent protection, sequential control, remote startup and shutdown, fault alarm and the like can be expanded, and intelligentization of an electronic product is improved.

Description

technical field [0001] The invention belongs to the field of electronic information, and in particular relates to a protection circuit and a control method for a single-chip microcomputer to detect a power supply voltage. Background technique [0002] Power converters are used in many AC power supply or DC power supply equipment, through which the unstable power supply voltage is converted into various stable voltages required by instruments and equipment. Generally, the power converter itself has a limit on the input power supply voltage range. When using electronic equipment with a power converter, if the external power supply voltage is abnormal or the operator makes an operation error, the electronic equipment is connected to an out-of-range power supply voltage, causing damage to the equipment. This is a very serious loss for valuable electronic equipment. In order to avoid damage to electronic equipment due to improper operation or abnormal supply voltage, it is neces...

AI Technical Summary

Problems solved by technology

Although this solution can protect electronic equipment, since this solution relies on the voltage breakdown characteristics of the Zener diode, for this protection method, the implementation of the power converter undervoltage protection function will add additional circuits, and at the same time Increase the cost, so the application of this scheme is more restricted

[0005] The overvoltage and undervoltage protection circuit is implemented in the form of a comparator. This is a commonly used scheme in power converters. In this scheme, overvoltage protection requires a comparator channel, and undervoltage protection also requires a channel. Each channel is set with a negative Feedback forms the hysteresis voltage at the over-voltage and under-voltage protection points to avoid malfunctions at the critical point of protection. This scheme has high precision and the characteristics that the protection voltage point can be adjusted arbitrarily has been widely used. However, for this scheme, the over-, Undervoltage protection requires two comparator channels, and also requires an accurate and stable reference voltage and a negative feedback circuit for each channel. The circuit is more complicated

This protection scheme is mainly used in equipment with sufficient volume and ordinary protection functions, but the application of this scheme is restricted by the requirements of today's electronic products with small size, full functions and high reliability, especially in some sizes. The demanding high-precision equipment is even more unable to meet its needs

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