SU725223A1 - Device for testing analogue-digit converters - Google Patents

Description

go-digital converter — with the first input of a code comparison device, the second input of which is connected to the output of the reversible counter, and the first, second and third outputs are connected respectively to the input of the pulse generator and to the third and fourth inputs of the reversible counter, the fifth input of which is connected to the output of the pulse generator and to the input of the second frequency divider.

The structural electrical circuit of the device is shown in the drawing.

The device contains an input signal source 1, an exemplary analog-to-digital converter 2 (ADC), a frequency multiplier 3, a gate 4, a trigger 5, a code comparison device 6, a reversible counter 7, an analog-to-digital converter 8 (ADC) being tested, an OR 9 element , delay line 10, generator of pulses, frequency divider 12, counter 13, recording device 14, frequency divider-15 with variable division factor, switch 16.

The arbitrary waveform is supplied from the output of source 1 of the input signal to the inputs of multiplier 3, which specifies n conversion points of the input voltage over a period, and the measurement inputs of the sample analog-digital converter 2 and the analog-digital converter 8 being tested.

In the initial state, the valve 4 is closed by the potential of the trigger 5, the counter 13 records the number 2 - t, where K is the number of bits of the counter, and t is the number of periods of measurement of the input voltage.

The measurement process begins after the input of the trigger 5 of the command pulse from the button 17 when the switch 16 is set to position 18. From the output of the valve 4, through the element OR 9, the pulse arrives at the start of the analog-digital converters 2, 8 and translates in the tested analog-digital converter 8 to the reversible counter 7. Next, the conversion result falls on one of the inputs of the code comparison device 6, to another input of which the result X is simultaneously fed An analog-to-digital converter 2.

Comparison device 6, depending on the results of the conversion, produces one of three signals:,,, while the first two prepare the operation of the reversible counter 7, respectively, in subtraction or addition relays. In the absence of a signal, the pulse generator 11 generates counting pulses entering the reversible counter 7, which changes its state until the device 6 gives a signal that blocks the operation of the generator And,

The pulses of the generator 11 are fed to the recording device 14 through the divider 15 frequency. After the measurement periods, the output pulse of the counter 13 returns the trigger 5 to the initial state, the valve closes and the average error for the period which is equal to

)

Az

where t is the number of conversion periods;

n - the number of transformations in the period; f-1, 2 ...; / - 12 ... ;

X is the result of a sample ADC conversion;

Y is the result of the conversion of the tested ADC.

In standby mode, the switch 16 is set to position 19 and the command pulse from the button 17 is fed directly to the start of converters 2, 8.

The proposed device for testing analog-to-digital converters allows automating the checking and issuing; The results are parallel codes, since the readings of the recording device immediately give an error value.

Claims (2)

1. Shtl Ndin VM “Digital electrical measuring instruments. M., “Energie, 1972, p. 290--340. 2. USSR author's certificate number 337932, cl. H OZK 13/02, 1969. I ffxod