Elastic-static discharge (ESD) protective circuit structure improving total harmonic distortion (THD) of high-speed analog-to-digital converter

Abstract

The invention relates to an ESD protective circuit structure improving the THD of a high-speed analog-to-digital converter, which comprises a signal input end, a power end and a ground end. A first diode is connected between the signal input end and the power end in the forward direction, and a second diode is connected between the ground end of the signal input end in the forward direction, wherein the second diode is from P+ to N well. According to the ESD protective circuit structure for improving the THD of the high-speed analog-to-digital converter, the diode from P+ to N well is connected between a signal line and a power line, and the diode from P+ to N well is also connected between the ground wire and the signal line, so that rate of capacitance change is relatively low when the ESD structure is employed, and distortion in the locus mode is not generated when high-frequency analog signals are input; and thus the THD of the input signals is effectively improved via the ESD protective circuit structure, circuit structure is simple and practical, work performance is stable and reliable, and application range is relatively wide.

Description

technical field [0001] The invention relates to the field of integrated circuits, in particular to the technical field of electrostatic discharge (ESD) protection circuits, in particular to an electrostatic discharge protection circuit structure for improving the total harmonic error of a high-speed analog-to-digital converter. Background technique [0002] In modern society, with the continuous development of science and technology, integrated circuits have been widely used on a large scale, and integrated circuits are widely used in various electronic and electrical equipment. However, due to the existence of static electricity, it will cause many problems in the use of integrated circuits. , Static electricity is generated from various frictions, and the discharge of static electricity will damage electronic components to varying degrees. [0003] Therefore, ESD (Electro-Static discharge) technology has appeared in the prior art, which literally translates as electrostati...

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Problems solved by technology

[0006] In the prior art, see figure 1 and figure 2 As shown, the usual ESD protection circuit uses an NMOS field effect transistor whose gate is grounded and a PMOS field effect transistor whose gate is connected to a power supply. When an analog signal is input, a large capacitance change will occur, resulting in a circuit with an input source The non-linear RC filter of the resistor will cause very obvious track mode distortion when the high-frequency signal is input. The biggest disadvantage is that when the input voltage changes, the signal of the node to the ground and power supply also changes greatly, resulting A larger total harmonic error (THD, Total Harmonic Distortion)

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