SU1686699A1 - Digital-to-voltage converter - Google Patents

Description

(21) 4725377/24

(22) 07.26.89

(46) 10/23/1. Bul №39

(72) A.S. Vederkin, V.A.Dunaev and Z.O.Zoidze

(53) 681.325 (088.8)

(56) Shilo V.L. Functionally analog integrated circuits. M .: Radio and Communication, 1982.

Titze U. and others. Semiconductor circuitry .- M .: Mir, 1983, p. 452, fig. 24.15. (54) CODE-VOLTAGE CONVERTER

(57) The invention relates to automation and can be used to convert digital codes into a video signal in image processing systems. The purpose of the invention is to expand the field of application by providing an independent setting of the initial and final values of the conversion scale. Converter code - voltage contains a code-controlled matrix 1, first 2 and second 3 converters 3 currents into voltage and summing amplifier 4. A positive effect is achieved by setting the corresponding values of the current-to-voltage converters conversion factors. 1 il.

T

cl

with

about

00

oh oh u

The invention relates to automation and can be used to convert digital codes into a video signal in image processing systems.

The purpose of the invention is to expand the field of application by providing an independent setting of the initial and final values of the conversion scale.

The drawing shows the functional circuit converter code - voltage.

Converter code - voltage contains code-controlled matrix 1, first 2 and second 3 current-to-voltage converters and summing amplifier 4.

Converter code - voltage works as follows.

When the converted NBX code arrives at the digital inputs of the code-controlled matrix 1, the currents AND and 12, respectively, are formed on the first and second outputs of the code-controlled matrix 1, respectively

UI I / D - °. BX t BX,

II UO / KM - -Q- - - s -,

Ko 22

,

where Uo is the value of the reference voltage;

RM Ro NBx / 2n is the internal resistance with respect to the first output of the code-controlled matrix 1;

RO is a code control matrix 1 parameter;

n is the size of the code to be converted;

  UO / RO is the maximum value of current at the outputs of code-controlled matrix 1.

Using the first 2 and second 3 current converters to voltages, the currents h and 2 are converted to voltages Ui and U2, respectively.

Ui IiRi; IR2-liR2, where RI and Ra are the conversion factors for current-to-voltage converters 2 and 3, respectively.

When implementing current to voltage transducers on operational amplifiers

their conversion factors are numerically equal to the resistance of the resistors included in the feedback circuit of the operational amplifiers.

As a result of the summation of the voltage Ui and Da by the summing amplifier 4 at the output of the latter and the output bus, code generator - voltage signal is generated, equal to

UBUx Ui + U2% +

2n

N

+ K2R2 (1-p,

where Ki and 2 are the transfer coefficients of summing amplifier 4 with respect to its first and second inputs, respectively.

It follows from the expression for Kvykh that, by changing the KiRi and KaRa Values, it is possible to independently set the initial and final values of the conversion scale, the converter code - voltage.

Claims (1)

Invention Formula A code-voltage converter containing a code-controlled matrix, the analog input and digital inputs of which are respectively the input voltage of the reference voltage and the input bus of the conversion code, and the first and second outputs of the code-controlled matrix are connected to the inputs of the first and second, voltage, characterized in that, in order to expand the scope of application by providing an independent setting of the initial and final values of the conversion scale, a summing amplifier is introduced into it The output of which is an output bus, and the first and second inputs are connected to the outputs of the first and second current-to-voltage converters, respectively.