High-precision fast-integration type AD (Analog-Digital) converter based on single chip microcomputer

Abstract

The invention relates to a high-precision fast-integration type AD (Analog-Digital) converter based on a single chip microcomputer, comprising an integrated signal control circuit, an integrator, a level comparison circuit and a single chip microcomputer. The integrated signal control circuit comprises resistors R1, R2, R3 and R4 and analog electronic switches K1, K2, K3 and K4; the integrator comprises an operational amplifier and a capacitor C; and the voltage comparison circuit comprises three high-speed comparators, i.e. a low voltage comparator, a high voltage comparator, a zero-crossingcomparator; and UNK, SC, FC and RC signals output by the single chip microcomputer are respectively connected with the controlled end of the analog electronic switches K1, K2, K3 and K4 and control the on-off of the analog electronic switches. The converter is directly controlled by the single chip microcomputer, and an external counter and a programmable logic device are omitted, thus, the circuit is simplified, the cost is reduced, and the converter is more easily combined with an AD application system.

Description

technical field [0001] The invention relates to an AD converter, in particular to a high-precision and fast integral AD converter based on a single-chip microcomputer. Background technique [0002] AD converters are often used in the technical field of digital processing of analog signals. Common AD converter types mainly include parallel comparison AD, successive comparison AD, Σ-A modulation AD and integral AD. Parallel comparison AD adopts multiple comparators, and the conversion can be realized by only one comparison. The conversion rate is extremely high, but the circuit scale is large and the price is also high; High and low power consumption, but it is not easy to achieve high resolution; Σ-Δ type is easy to achieve high resolution, the main disadvantage of Σ-Δ type AD is that the filter that converts duty information into digital output is extremely complicated; integral type Since the AD converter came out, it has been widely used in low-speed conversion occasions....

AI Technical Summary

Problems solved by technology

Parallel comparison AD adopts multiple comparators, and the conversion can be realized by only one comparison. The conversion rate is extremely high, but the circuit scale is large and the price is also high; High and low power consumption, but it is not easy to achieve high resolution; Σ-Δ type is easy to achieve high resolution, the main disadvantage of Σ-Δ type AD is that the filter that converts duty information into digital output is extremely complicated; integral type Since the AD converter came out, it has been widely used in low-speed conversion occasions. Its main advantages are good linearity and high sensitivity, especially in suppressing power frequency interference. The rate is very low; at present, there have been papers published on the low conversion rate of the integral AD converter, such as the title published in "Microcomputer Information" (Embedded and SOC) 2006, Volume 22, No. 1-2 A new method was proposed for the paper "Application of Programmable Logic Devices in Integral AD Converter". Although the conversion rate of the integral AD converter has been improved, the technical solution is still complicated

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