Input protection circuit

Abstract

The invention relates to an input protection circuit which is connected with a DC-DC power-supply chip. The input protection circuit includes an overcurrent and overvoltage protection circuit which is connected with an input signal and outputs a secondary signal and a secondary protection circuit which is connected with the secondary signal. The secondary protection circuit includes a first capacitor, a positive electrode of which is connected with the secondary signal, a triode, a collecting electrode of which is connected with the secondary signal, a voltage-stabilizing diode, a negative electrode of which is connected with a base electrode of the triode, a schottky diode which is connected in parallel with the triode, a resistor which is connected serially between the secondary signal and the negative electrode of the diode, a second capacitor and a third capacitor, which are connected in parallel with the voltage-stabilizing diode and a fourth capacitor, a positive electrode of which is connected with an emitting electrode of the triode. A negative electrode and a positive electrode of the schottky diode are connected with the collecting electrode and the emitting electrode of the triode respectively. The emitting electrode of the triode is connected with the DC-DC power-supply chip. When the input protection circuit is connected to the DC-DC power-supply chip, normal and reliable operation of the whole system can be ensured and at the same time, the power-supplying range of the system is increased.

Description

technical field [0001] The invention relates to an input protection circuit. Background technique [0002] With the increasing importance of energy saving and emission reduction, the design of embedded systems increasingly considers issues such as power consumption and efficiency. More and more systems abandon the traditional linear voltage regulation circuit and adopt DC-DC power supply circuit (DC to DC switching power supply). The advantages of DC-DC converter are high efficiency, large output current and small static current. [0003] However, the operating environment of the current embedded system is diversified, and it is difficult to guarantee the quality of power supply in various operating environments. And affected by the chip manufacturing process, the input voltage range of the DC-DC power supply chip has a certain limit. If the supply voltage exceeds the limit, the DC-DC power supply chip will be damaged and the entire system will fail. [0004] In view of th...

AI Technical Summary

Problems solved by technology

[0003] However, the current embedded system operating environment is diversified, and it is difficult to guarantee the quality of power supply in various operating environments.

And affected by the chip manufacturing process, the input voltage range of the DC-DC power chip has a certain limit. If the supply voltage exceeds the limit, the DC-DC power chip will be damaged and the entire system will fail.

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