Port protecting circuit capable of preventing inverse current leakage

Abstract

The invention discloses a port protecting circuit capable of preventing inverse current leakage. The port protecting circuit capable of preventing the inverse current leakage comprises a resistor, a power supply, a first phase inverter, a second phase inverter, a NOR gate, a first PMOS transistor, a second PMOS transistor, a first NMOS transistor, a second NMOS transistor, a third NMOS transistor, a fourth NMOS transistor, a fifth NMOS transistor and a sixth NMOS transistor. According to the port protecting circuit capable of preventing the inverse current leakage, when a voltage of the output end of the protecting circuit is lower than 0 V, the current is effectively prevented from inversely flowing out of an output port from the ground, and meanwhile when the voltage of the output end is higher than a power supply VDD, the large current is prevented from damaging a chip, and thus the service life of the chip is guaranteed.

Description

Technical field [0001] It relates to the field of integrated circuits, especially a port protection circuit. Background technique [0002] The output ports of traditional integrated circuits such as figure 2 As shown, during normal operation, the PMOS tube and the NMOS tube are controlled by the signal DI to drive the external load, and the voltages of the output ports A and B should be between the power supply voltage VDD and 0V. However, in actual conditions, the output port may be higher than the chip power supply voltage VDD or lower than 0V, which causes the port to draw current from the ground terminal or the forward working current is too large, and the chip cannot work normally or even be damaged; Technology has not yet solved such problems. Summary of the invention [0003] In order to solve the shortcomings of the prior art, the purpose of the present invention is to provide a port protection circuit to prevent reverse leakage; this protection circuit effectively preven...

AI Technical Summary

Problems solved by technology

However, in actual conditions, the output port may be higher than the chip power supply voltage VDD or lower than 0V, which will cause the port to draw current from the ground terminal or the forward working current is too large, so the chip cannot work normally or even be damaged; Technology has not yet solved such problems

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