SU783979A1 - Analogue-digital converter - Google Patents

Description

(54) ANALOG-DIGITAL CONVERTER

one

The invention relates to the field of computing and digital measurement technology and can be used to convert analog values to digital values. 5

A analog-to-digital converter is known, comprising a comparator, a reversible counter, a digital-to-analog converter and a fl.

This converter has a complex metrological control.

Also known is an English-to-digital converter containing a reversible pulse counter, a digital-to-analog converter, a logic device, a J5 control unit, a reference element, the first input of which is connected to the input of an analog-digital converter, the second input of the comparison element is connected to the output of a digital analog converter. , the output of the comparing element "n" with the first input of the logic device, the first output of which is connected to the first information input of the reversing 25 pulse counter, the second output logical device connected to the control input of the reversible account; snip pulses, a reversible pulse counter output is connected to vhodomzo

a digital-to-analog converter; the first output of the control unit is connected to the second input of logic device 2.

The disadvantage of this converter is a complex metrological control of the linearity of the output characteristic, which is carried out manually.

The purpose of the invention is to automate the Metrological control.

The goal is achieved in that an analog-to-digital converter containing a reversible pulse counter, a digital-to-analog converter, a logic device, a control unit, a comparison element, the first input of which is connected to the input of the analog-digital converter, the second input of the comparison element is connected to the digital-analog output converter, the comparison element output is connected to the first input of the logic device, the first output of which is connected to the first information input of the reversing counter pulses, the second output of the logic device is connected to the control input of the reversible pulse counter, the output of which is connected to the input of the digital-to-analog converter. The first output of the control unit is connected to the second input of the logic device, the pulse counter, the code analysis unit and the code reduction unit are introduced to the minimum form, the output of the reversible pulse counter is connected to the input of the code leading block to the minimum form and the information input of the anesthesia block of the code whose output is connected to the second the reversal pulse counter input, the output of the code leading block is minimally connected to the first output of the analog-digital converter, the output of the logic device is connected to the information input of the pulse counter, the output of which is connected to the second output of the analog-digital converter, control inputs, pulse counter, and the code analysis block is connected respectively to the second and third turns of the control block,

. The essence of the invention is in a drawing by drawing, which shows a functional electrical circuit of the analog-digital converter.

Input 1 of the digital-to-analogue converter i is connected to the first input of the comparison element 2, the second output of which is connected to the output; digital-to-analog converter 3. The VALUE of the comparison element 2 is connected to the first input of the logic device 4, providing switching of the counting modes in the reversible pulse counter 5 and the operation of the pulse counter b . The first output of the logic unit 4 is connected to the first information input of the reversible pulse counter 5, which is intended for forward and backward pulse counting as well as for the execution of the convolution and sweep code.

The second output of the logic device 4 is connected to the control input of the reversible pulse counter 5. The output of the reversing counter 5 is connected to the input 1 of the analog converter 3, the input of the code to the minimum form 7 and the informative input of the code analysis block 6, intended to highlight the most significant bit yes code. The output of the code-reduction unit to minimum form 7, which performs the operation to bring the code to minimum form, is the first output 9 of the analog-to-digital converter.

 The output of the code analysis unit 8 is connected to the second information input of the reversible pulse counter 5. The third input of the logic device 4 is connected to the information input of the pulse counter b intended for counting the pulses. The output of the pulse counter b is the second output 10 of the analog-digital converter. The operation of the converter in the coding mode and metrological control is ensured by the block, control 11.

Offered # 1-analog-to-digital converter (ADC) operates in two modes: the mode of direct conversion of analog value to digital and the mode of metrological control of linearity of the output characteristic.

The process of converting an input analog value to a p-code is carried out according to the following balancing method,

In the direct conversion mode of the input analog, the value of the p-ACID ACI works as follows.

The input analog value is fed from the input 1 of the converter to the first input of the comparison element 2, which compares the input analog value with the value of the feedback signal coming from the output of the DAC. The difference between the above values is converted into a digital code with a PS of logic unit 4, reuser pulse counter 5 and control unit 11. The result of the conversion, generated in a reversible pulse counter 5, in the case of direct counting is presented in minimal form, and the reverse in non-minimal.

The direct counting of pulses in the reversible counter 5 is carried out by performing a code convolution operation, and the reverse counting is performed using a sweep operation. To reduce the result of the conversion to the minimum form, use the block to reduce the code to the minimum form 7.

The metrology control of the linearity of the output characteristic of the converter begins with a check that the (p + 2) th digit of the ADC complies with its metrological characteristics. In this case, it is assumed that the (p + 1) low-order bits are tuned, a stepwise increasing value is supplied to the ADC input, and t is a step of which is used to check the -th bit. The process of control consists of two etanos. At the first stage, the conversion of the t value of the step to the code by the method described above is performed. At the second stage, the checked (most significant) times, p and the received code are eliminated.,; By performing convolution and sweep operations of the code in a reversible pulse counter 5.

For example, the code combination 010001000, containing a unit in the seventh (senior) bit, is replaced by the combination 00101111. The coding process then continues, and if

Claims (1)

Claim An analog-to-digital converter containing a reversible pulse counter, a digital-to-analog converter, a logic device, a control unit, a comparison element, the first input of which is connected to the input of the analog-to-digital converter, the second input of the comparison element is connected to the output of the digital-to-analog converter, the output of the comparison element connected to the first input of the logical device, the first output of which is connected to the first information input of the reversible pulse counter, the second output of the logical device and connected to the control input of the reversible pulse counter, the output of which is connected to the input of the digital-to-analog converter, the first output of the control unit is connected to the second input of the logic device, characterized in that, in order to automate metrological control, a pulse counter, a code analysis unit and a block are introduced into it reducing the code to the minimum form, and the output of the reverse pulse counter is connected to the input of the block bringing the code to the minimum form and the information input of the code analysis block, the output to connected to the second information input of the reversible pulse counter, the output of the code conversion unit is connected to the first output of the analog-to-digital converter to the minimum form, the third output of the logic device is connected to the information input of the pulse counter, the output of which is connected to the second output of the analog-to-digital converter the inputs of the pulse counter and the analysis unit -code are connected respectively to the second and third outputs of the control unit.