Integrated circuit for suppressing high impedance input end current leakage

Abstract

The invention discloses an integrated circuit for suppressing high impedance input end current leakage. The integrated circuit comprises a printed circuit board of which the top layer and the bottom layer are ground planes and the intermediate layer is a wiring layer; multiple function selection switches which are welded on the top layer or the bottom layer of the printed circuit board, wherein the output pins of the multiple function selection switches are respectively coupled with different external function pins and the control pins of the multiple function selection switches are respectively coupled with external control pins; and a voltage following circuit which is welded on the bottom layer or the top layer of the printed circuit board, wherein the input pin of the voltage following circuit is coupled with input voltage and the output pin of the voltage following circuit is coupled with the input pins of the multiple function selection switches through the intermediate layer of the printed circuit board so as to form equipotential shielding rings. According to the designed integrated circuit, the input ends of the multiple function selection switches are enabled to be maintained to be equipotential under the state of whether the function selection switches are conducted so that the input ends of the function selection switches which are not conducted are enabled not to generate leakage current due to potential difference with other devices.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to an integrated circuit for suppressing current leakage at a high-impedance input terminal. Background technique [0002] Digital multimeter, a multi-purpose electronic measuring instrument, generally includes the functions of ammeter, voltmeter, ohmmeter, etc. It is sometimes called multimeter, multimeter, multimeter, or three-purpose meter. [0003] In order to realize the above functions such as ammeter, voltmeter, ohmmeter, etc., the digital multimeter needs to switch between different measurement functions through a function selection circuit; When there is a potential difference between different pins, a small current leakage will occur, and the leaked current will cause a voltage drop on the front-end input resistance and the output resistance of other functions, causing a certain measurement error, and its influence will vary with the Varies with the amount of le...

AI Technical Summary

Problems solved by technology

[0003] In order to realize the above functions such as ammeter, voltmeter, ohmmeter, etc., the digital multimeter needs to switch between different measurement functions through a function selection circuit; When there is a potential difference between different pins, a small current leakage will occur, and the leaked current will cause a voltage drop on the front-end input resistance and the output resistance of other functions, causing a certain measurement error, and its influence will vary with the Varies with the amount of leakage current and cannot be removed by software

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