A circuit for improving the analog-to-digital conversion precision of single chip microcomputer

Abstract

The invention provides a circuit for improving the analog-to-digital conversion precision of a single chip microcomputer, mainly comprising a single chip microcomputer U6, an amplifier U4, a comparator U5, an analog switch U1, an analog switch U2, an analog switch U3 and an integrating capacitor C1. The invention provides a high precision analog-to-digital conversion circuit consisting of a singlechip microcomputer counter, an external universal amplifier, an analog switch and a resistor-to-capacitor component. The acquisition accuracy can reach 216=65535 units, which is 64 times higher thanthat of the single chip microcomputer with 10-bit A / D conversion channel. The circuit can make up for the limitation of single chip microcomputer system in A / D conversion and broaden the application prospect of single chip microcomputer system.

Description

technical field [0001] The invention belongs to the technical field of acquisition signal processing, and in particular relates to a circuit for improving the precision of analog-to-digital conversion of a single-chip microcomputer. Background technique [0002] In the control of high-pressure common rail fuel system, the acquisition accuracy of analog quantity is one of the key technologies that affect the quality of system control. At present, the commonly used method is to use the analog-to-digital conversion channel of the single-chip system itself for data acquisition, and its acquisition accuracy can reach 2 10 = 1024 units, such acquisition accuracy cannot meet the requirements of precise testing. Generally, it is necessary to expand the high-precision A / D analog-to-digital conversion chip to improve the acquisition resolution and achieve high-precision control. [0003] But this will increase the cost of the control system, and because the extended chips generally r...

AI Technical Summary

Problems solved by technology

At present, the commonly used method is to use the analog-to-digital conversion channel of the single-chip system itself for data acquisition, and its acquisition accuracy can reach 2 10 = 1024 units, such acquisition accuracy cannot meet the requirements of precise testing. Generally, it is necessary to expand the high-precision A / D analog-to-digital conversion chip to improve the acquisition resolution and achieve high-precision control

[0003] But this will increase the cost of the control system, and because the extended chips generally require parallel or serial interfaces for processing, the interface resources for the single-chip microcomputer are wasteful

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