SU974566A1 - Integrating voltage-to-code converter - Google Patents

Description

The invention relates to measuring and computing techniques and is used in information and computing systems.

A device for integrating balancing of transformed values (voltages or currents) is known with reference values (voltages or currents) containing an integrator, the first and second inputs of which are connected to an input bus of a device and the buses of a source of reference voltages, respectively, and the output connected with the first input of the comparator unit, the second input of which is connected to the common bus of the device, and the output is connected to the input of the control and code generation unit, the outputs of the latter are connected to the control inputs to mmutator and integrator 1}

The disadvantage of this device is the low conversion accuracy.

A device for integrating balancing with a variable duration of cycles of converted values (voltages or currents) using reference values is known, which contains an integrator, the first, second and third inputs of which are connected through a switch

with the device input bus and with the reference voltage source bus, respectively, the integrator output is connected to the first input of the comparison unit, the second input of which is connected to the reference voltage source bus, and the output to the input of the control and code generation unit, the outputs of which are connected to the upn inputs the switch and integrator of the University.

The disadvantage of this device is the low conversion accuracy.

15

It is also known device containing the first and second integrators, while the input of the first integrator through the switch is connected to the input

20 by the device bus, the input of the second integrator through the switch is connected to the source voltage buses of the reference voltage, the outputs of the first and second integrators are connected to the inputs of the comparison unit, the output of which is connected to the input of the control unit and code generation, the outputs of the latter are connected to the control inputs of the first switch and the second integrato30 rovGz.

The balance of this device is low conversion accuracy and reliability.

The purpose of the invention is to increase the reliability and accuracy of the conversion device.

The goal is achieved by integrating a voltage converter into a code containing the first integrator, the first input of which is connected to the input bus through a switch, the second input to the first output of the control and code generation unit, and the output to the first input of the comparison unit, the second input of which is connected to the output of the second integrator, the first input of which is connected to the first output of the control and code generation unit, the second input through the switch is connected to the reference voltage source bus, first, second and third second switch control inputs are connected respectively to the second, third and fourth output of the control unit and generating a code having an input connected to the output of comparison block, a third input of the first integrator via a switch coupled to the bus voltage reference source.

Fig. 1 shows a structural electrical circuit of the device; Fig. 4 shows voltage change diagrams.

The circuit contains the integrators 1 and 2 switch 3, the input bus 4 of the device, the bus 5 of the source of the reference voltage, the comparison unit 6, the control and code generation unit 7.

The first input of the integrator 1 through the switch 3 is connected to the input bus 4 of the device. The second input of the integrator 1 and the input integrator 2 through the switch 3 is connected to the bus 5 of the reference voltage source. The outputs of the integrators 1 and 2 are connected to the inputs of the comparison unit b, the output of which is connected to the input of the control and code generation unit 7. The outputs of the control and code generation unit 7 are connected to the control inputs of the switch 3 and the integrator 1 and 2.

The device works as follows.

Before starting the conversion, the signal from the control block 7 and the code generation of the integrator 1 and 2 are zeroed. In the first conversion cycle (Fig. 2), the voltage U from the input bus 4 of the device is transferred by the switch 3 to the first input of the integrator 1. The reference voltage U from the bus 5 of the source of the reference voltage by the switch 3 is transmitted to the input of the integrator 2. During the time T the integrators 1 and 2 integrate the voltage with the same time constant. Voltages from the outputs

Integrators 1 and 2 are received at Comparison Unit 6, where they are compared and the generation of the x and x signals of the comparison result. The signals x and x; are used in the control and code generation unit 7 to control the conversion in the next cycle. If U ,, p g 1), then in the second conversion cycle, the reference voltage Up is transmitted to the second input of the integrator 1 by the control signal of the switch 3. For the case and, the reference voltage Ujj is kept connected to the input of the integrator 2. In the second and Subsequent conversion cycles, the first input of integrator 1 is disconnected from the input bus 4 of the device. The second also converts the reference voltage I., integrates over time T / 2, either by integrator 1 or by integrator 2. Next, HOBOR compares the voltages at the outputs of integrators 1 and 2 and produces comparison signals X2 and x. The following also converts over time T / 2 the reference voltage DO integrates, increasing the voltage u, p. or ypi in such a way that the voltage difference between them decreases.

Similarly, the balancing cycles are performed with the integration of the reference voltage UQ during the subsequent time intervals -2T

where-1b5i, apkio-

According to the results of comparison,. and l block 7 of the control unit X, and the formation of the code generates the code of the voltage being converted

.S (X-Xji

When converting alternating voltages Uy, instead of the reference voltage Up, in the first conversion cycle to the input of the integrator 2, the switch 3 applies a zero voltage from the common bus of the reference voltage source. The change / voltage diagrams and vP-2 transformations of positive voltages Uy are shown in FIG. 3, and in the transformation of negative voltages and in FIG. four.

Improving the accuracy of conversion is achieved through the use of a source of unipolar reference voltage, since there is no component of error due to the presence of the second source of reference voltage and its nonidentity with the first.

Thus, the proposed mouth. This feature provides an increase in reliability and accuracy of conversion of voltage to code.

Claims (3)

1.Balakai V.G. and others. Integrated circuits of analog-digital and digital-analog converters. M., Energie, 1978, p. 62.67. 2. For the war of Germany No. 2052753, cl. 21 a36 / 00, 1971. 3. For Germany FRF 2404597, Cl, 21a 36/00, 1980 (prototype).