A filter circuit and chip based on mos field effect transistor

Abstract

Some embodiments of the present application provide a filter circuit and chip based on MOS field effect transistors. The filter circuit includes a first MOS field effect transistor and an electrostatic discharge unit; during normal operation, a filter capacitor is formed between the gate of the first MOS field effect transistor and the substrate; when an ESD event occurs, the electrostatic discharge unit and the first A MOS field effect transistor forms a discharge path that transfers the accumulated electrostatic charge to ground. In the embodiment of the present application, on the basis of the first MOS field effect transistor, an electrostatic discharge unit is added, so that the capacitance characteristics and the characteristics of the ESD discharge path required between the power supply and the ground are combined in the same circuit, so that the circuit can be used in the same circuit. It exhibits capacitive characteristics during normal operation; when an ESD event occurs between the power supply and ground, it provides an ESD discharge path to play the role of ESD protection, thereby improving the ESD capability of the chip.

Description

technical field [0001] The present application relates to the technical field of integrated circuits, in particular to a filter circuit and chip based on MOS field effect transistors. Background technique [0002] In the final stage of chip design, a filter circuit from power supply to ground is generally added to the spare part of the chip. The selected filter capacitor can be MOS (Metal-Oxide-Semiconductor, metal-oxide-semiconductor) field effect transistor capacitor, MIM (Metal-Insulator-Metal, metal-insulator-metal) capacitor, MOM (Metal-Oxide-Metal, metal-oxide-metal) capacitors, etc. However, considering that the capacitance per unit area of ​​MOS field effect transistor capacitors (hereinafter referred to as MOS capacitors) is larger than that of other capacitors, a larger capacitor can be obtained under the same area. Therefore, under normal circumstances, MOS capacitors are usually selected as filter capacitor. [0003] MOS capacitors are divided into two types: ...

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Problems solved by technology

This kind of filter circuit generally only has capacitance characteristics, and does not have ESD (Electro-Static discharge, electrostatic discharge) characteristics. How...

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