Simulative switch circuit structure

Abstract

The invention relates to a simulative switch circuit structure. The simulative switch circuit structure comprises a phase inverter circuit module, a passage geminate transistor circuit module and a breaking point protection circuit module, wherein an input end of the phase inverter circuit module is connected with a control signal input terminal (CRT), the passage geminate transistor circuit module is connected between a signal input end (IN) and a signal output end (OUT), the passage geminate transistor circuit module comprises a third P-channel Metal Oxide Semiconductor (PMOS) field effect tube (P3), an output end of the phase inverter circuit module is connected with a grid electrode of the third PMOS field effect tube (P3), and a substrate of the third PMOS field effect tube (P3) is connected with a power source (VDD) or the signal input end (IN) through the breaking point protection circuit module. According to the simulative switch circuit structure, the phenomenon that an input signal leaks power to the VDD through a parasitic diode which is arranged between a field effect tube source electrode and the substrate is avoided, normal turn-off of the simulative switch in a power source power off condition is achieved, the linkage current from the input end to the power source is avoided, and the simulative switch circuit structure is simple in structure, practical, stable and reliable in working performance, and wide in application range.

Description

technical field [0001] The invention relates to the design field of semiconductor integrated circuits, in particular to the technical field of analog switches in semiconductor integrated circuits, and specifically refers to an analog switch circuit structure. Background technique [0002] At present, analog switches are widely used in the transmission and selection of analog signals. The transmission of various high-definition video and audio signals puts forward higher and higher requirements on the performance of analog switches. [0003] In order to transmit a voltage close to the power supply (VDD), the traditional analog switch circuit uses a symmetrical connection between PMOS and NMOS transistors in the transmission channel. The substrate (B end) of the PMOS is connected to VDD, and a parasitic diode is formed between S and B of the PMOS. When VDD is powered off and there is a signal at the input terminal, it will cause the leakage of the parasitic diode from the in...

AI Technical Summary

Problems solved by technology

In order to reduce the on-resistance of the circuit, the substrate of the channel PMOS is connected to the input terminal when it is turned on. When this analog switch is powered off, the input signal will also leak to the output terminal.

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