Novel high-stability isolating switching circuit for negative pressure application

Abstract

The invention discloses a novel high-stability isolating switching circuit for negative pressure application. In a case where negative voltage is present at both ends of a switching circuit, if the substrate of a common MOS transistor switch is fixedly connected with the source or the drain of the common MOS transistor switch, it is highly possible to switch on both switched-off ends of the MOS transistor or to form an on-state diode when the voltage on both ends of the switch changes, thereby deteriorating the isolation performance of the switch. For such case, the invention invents the novel high-stability isolating switching circuit for negative pressure application. The switching circuit can ensure that the switch cannot be switched on regardless of how the voltage on both ends of the switching circuit changes when the switch is switched off, can achieve stable isolation, and can normally operate when being closed.

Description

technical field [0001] The invention mainly relates to the field of negative pressure applications, in particular to a novel high-stability isolating switch circuit for negative pressure applications. Background technique [0002] For analog integrated circuits, a module often needs a negative voltage circuit to achieve specific functions, but in order to control the negative voltage circuit with other circuits, it is necessary to add a switch circuit before its output interfaces with other circuits, so that the negative voltage circuit The piezoelectric circuit works normally with other modules when the switch is turned on, and is isolated from other modules when the switch is turned off, and does not affect the work of their respective circuits. However, sometimes as the environment changes, the original isolation may become conductive, causing the originally disconnected circuits to conduct and affect each other. For example, in negative voltage applications, by controll...

AI Technical Summary

Problems solved by technology

However, sometimes as the environment changes, the original isolation may become conductive, causing the originally disconnected circuits to conduct and affect each other.

For example, in negative voltage applications, by controlling the gate of a simple NMOS switch to disconnect the negative voltage circuit at both ends of the switch, the substrate of the NMOS transistor is fixedly connected to the source of the lowest potential, but as the external environment changes, it may cause The switch tube forms a forward-biased diode, so that the switch tube is turned on, which affects the work of its own module and also affects the work of other modules.

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