Rapid analog-to-digital conversion method and analog-to-digital converter

Abstract

The invention discloses a rapid analog-to-digital conversion method and an analog-to-digital converter. The analog-to-digital conversion method comprises steps that a precise regulated high power supply Ug and a precise regulated low power supply Ud form a precise voltage range, n serial reference divider resistors are connected with two ends of the precise voltage range, and reference voltages ofn comparators are formed due to voltage division; a to-be-tested analog voltage and a reference voltage are compared, and a turning point Uk exists in a comparison result; a next comparison voltage range is created based on the turning point Uk, the steps are recycled till set precision is obtained through comparison; and in the final comparison, the to-be-tested analog voltage U is a mean valueof Uk and U(k+1) and is output. According to the method, the next comparison is based on the previous comparison, comparison is not started from zero and is performed only in one comparison time, so that the comparison speed is improved.

Description

technical field [0001] The invention relates to an analog-to-digital conversion method and an analog-to-digital converter, in particular to a fast analog-to-digital conversion method and an analog-to-digital converter. Background technique [0002] The existing commonly used several analog-to-digital converters mainly include integral type, successive comparison type, parallel comparison type / serial-parallel comparison type, Σ-Δ modulation type, capacitor array successive comparison type, and voltage-frequency conversion type. The principle and main advantages and disadvantages of the digital converter are as follows: [0003] (1) The working principle of the integral type AD is to convert the input voltage into time (pulse width signal) or frequency (pulse frequency), and then obtain a digital value by a timer / counter. Its advantage is that high resolution can be obtained with a simple circuit, But the disadvantage is that because the conversion accuracy depends on the int...

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Problems solved by technology

[0003] (1) The working principle of the integral type AD is to convert the input voltage into time (pulse width signal) or frequency (pulse frequency), and then obtain a digital value by a timer / counter. Its advantage is that high resolution can be obtained with a simple circuit, But the disadvantage is that because the conversion accuracy depends on the integration time, the conversion rate is extremely low. Most of the initial single-chip AD converters use the integral type, and now the successive comparison type has gradually become the mainstream.

[0004] (2) Successive comparison AD is composed of a comparator and DA converter through successive comparison logic, starting from MSB, sequentially comparing the input voltage with the output of the built-in DA converter for each bit, and outputting digital numbers after n times of comparison Value, its circuit scale is medium, its advantages are high speed, low power consumption, cheap price at low resolution (12 bits)

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