Programmable voltage monitoring circuit

Abstract

The invention discloses a programmable voltage monitoring circuit, which comprises a program control circuit, a monitoring voltage generating circuit and a real-time voltage monitoring circuit. The program control circuit comprises a program state selecting end and a state judging circuit. The program state selecting end is for a user to select one from four program states i.e. input grounding, connecting power supply, suspending and suspended connection, etc. The state judging circuit generates corresponding control signal based on the program state selected by the user, and outputs that to the monitoring voltage generating circuit; the monitoring voltage generating circuit, based on the input control signal, generates a corresponding monitoring voltage and sends the monitoring voltage to the real-time voltage monitoring circuit; the real-time voltage monitoring circuit compares the monitored voltage and the voltage to be monitored and generates the corresponding monitoring results. The invention adds program states without increasing program pins and changing programming way, and enlarges the range of voltage coverable by the monitored circuit.

Description

technical field [0001] The invention relates to voltage monitoring, in particular to a programmable voltage monitoring circuit. Background technique [0002] In the general application of programmable voltage monitoring circuit at present, each programming pin has three states: connected to power supply, grounded and floating; each pin generates two switch control signals, which are used to control the input resistance of a non-inverting amplifier, the non-inverting Amplifiers have different amplification factors when the input resistance is different, so as to generate different monitoring voltages. This programmable voltage monitoring circuit has 3 N There are different voltage setting states, where N represents the number of programming pins. [0003] In the application of programmable voltage monitoring circuit, the following points should be paid attention to: [0004] 1) It is required that the values ​​of two adjacent monitoring voltages cannot be too far apart, ot...

AI Technical Summary

Problems solved by technology

[0009] First, when the programming accuracy is 0.1v (meaning that the difference between two adjacent monitoring voltages is 0.1v), and three programming pins are used, since the three pins can only have 3 N = 27 states, the variable range of programming is only 2.7v, which cannot cover the entire range from 1.8v to 5v. In order to expand the voltage coverage, it is necessary to increase the programming pins, which will cause loss of PCB area

[0010] Secondly, the circuit uses a non-inverting amplifier in the form of a resistor. When amplifying, the resistance of the amplifier forms a DC path to the ground potential, which will generate a large DC power consumption.

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