A voltage self-following anti-backflow circuit

Abstract

The invention relates to a voltage self-following anti-backflow circuit, comprising N diodes, a PMOS tube, and a resistor; the voltage input end of the voltage self-following anti-backflow circuit is connected to the anodes of the N diodes and the PMOS The drain of the tube, the voltage output terminal of the self-following anti-backflow circuit is connected to the cathodes of the N diodes and the source of the PMOS tube, and the gate of the PMOS tube is connected to the external control signal input terminal, so The external control signal input terminal can output high and low levels to control the on-off of the PMOS tube; one end of the resistor is connected to the source of the PMOS tube, and the other end is connected to the gate of the PMOS tube; the number N of the N diodes is Integer greater than 0. The circuit is used in the constant current charging and boosting discharge circuits of batteries or supercapacitor modules, which can not only prevent the leakage current from exceeding the standard and cause reverse irrigation, but also realize the precise control of the constant current charging cut-off voltage and the boosting and discharging voltage.

Description

technical field [0001] The invention relates to the technical fields of instrumentation and intelligent distribution network, in particular to a voltage self-following anti-backflow circuit. Background technique [0002] During the constant current charging process of charging the battery or supercapacitor module, if the input terminal of the constant current DC / DC chip is powered off, and there is a higher voltage at the output terminal at this time, the output of the constant current DC / DC chip will have no effect on the input. High leakage current, the leakage current will cause the constant current DC / DC chip to not work normally, such as hiccup-type repeated start, input and output direct connection, etc. Burned, or even the battery or supercapacitor module is short-circuited and exploded. Therefore, it is necessary to set up an anti-backflow circuit between the constant current charging DC / DC chip and the battery or super capacitor module to solve the above problems. ...

AI Technical Summary

Problems solved by technology

The circuit uses two MOS transistors to realize the anti-backfeed and the voltage at both ends of the anti-backfeed circuit is equal, but because the combination of the two MOS transistors requires that the gate level bound together must be a certain level state, it is not allowed Continuous change

If the voltage at both ends of the anti-backfeed circuit changes continuously, the circuit will not work

In the process of constant current charging, the output voltage of the constant current DC / DC chip increases with the continuous increase of the voltage of the battery or supercapacitor module, so the circuit cannot realize anti-backfeed and no voltage during constant current charging. loss of function

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