SU377806A1 - ALL-UNION Tfsji V * "V! * 'I" * e' C .. ''. '> &! TSB "Cl $ yg <^ G'; -;; ^ AND & LIO - ^^ ИА - Google Patents

Description

one

The invention relates to the field of functional signal conversion and can be used in digital and analog devices, in measurement and digital control systems.

Known functional converters that contain a linear digital-to-analog block connected to the input of the adder. In these, separate power sources are used to set the initial ordinates of the approximation areas and the slope angles of the polyline, and their switching is realized with the keys from the decoder.

The presence of separate power supplies and a decipher makes the circuit complicated, and with increasing accuracy the decoder circuit becomes more complex and the number of power supplies increases.

The proposed functional converter is characterized in that, in order to simplify the circuit, it contains a functional digital-analog block, the input of which is connected to the input of the linear digital-analog block and to the input of the device, and the output is connected to the second input of the adder, and a digital controlled resistor, one the end of which is connected to the output of the linear analog-digital block, the other one is connected to the tin of the zero potential,

2

the input is connected to the output of the functional digital-analog block.

The block diagram of the device is shown in FIG. one; in fig. 2 is a graph showing 5 the operation of the device.

It contains a linear digital-analog block L to the output of which is connected a digital controlled resistor (LRC) 2, a functional digital-analog block 3

0 and adder 4.

Argument X in the form of a binary code is fed to the input of a linear digital-analog block / and functional digital-analog block 3, the output of which

5 is summed at adder 4.

The device works as follows.

Line-in digital-to-analog input

block / lower code bits

argument X to form linear

0 plots / Cr approximating broken line. The slope coefficients of the sections vary depending on the value of Xi in the respective sections of the partition. The transition from / Ci to Ki + is done using SDG 2,

5 to which a linear digital-analog block 1 is loaded. Older bits X are fed to the input of an operating digital-analog block 3, the output of which when the argument reaches the abscissa values

The 0 partitioning sections of the reproducible function form the voltage corresponding to the value of m ordinates in the sections. The magnitudes of the ordinates Yi in any region and the corresponding coefficients of inclination of the regions Kg are related to one functional dependence with the value of the argument Xg on this region. Therefore, the weights of the resistances in the functional digital-analog block 3 and in SDG 2 are respectively equal and selected depending on the type of the reproduced function by one of the approximation methods. In this connection, the same signal controls the connection of the resistance both in the functional unit 3 and the corresponding resistance in SUR 2, therefore, the same logic elements are used for switching the resistance in the functional unit 5 and in SUR 2. .

The voltages from the outputs of the linear digital-to-analog block / and the functional digital-analog block 3 are summed on the adder 4, the output voltage of which corresponds to the value of the reproduced function (X).

Thus, using a lined digital-analog block /, a functional digital-analog block 3, LRC 2 and adder 4, a piecewise-linear approximation of the function with the required accuracy is performed.

Subject invention

A functional converter containing a linear digital-to-analog block connected to the first input of the adder, characterized in that, in order to simplify

circuits, it contains a functional digital-analog unit, the input of which is connected to the input of a linear digital-analog block and to the input of the device, and the output is connected to the second input of the adder, and digital

a controlled resistor, one end of which is connected to the output of a linear digital-analog block, the other is connected to a zero potential, and a control input is connected to the output of a digital-analog function block.