JPH0456517A - Analog data input circuit - Google Patents

Abstract

PURPOSE:To output an accurate analog data by detecting the conversion accuracy from an inputted analog data into a digital data to correct the gain of a buffer amplifier. CONSTITUTION:A reference data is always generated from a reference data generating section 2, a logic section 8 controls an analog data changeover section 3 to allow it to input the reference data into an A/D converter 5 through an AGC(Automatic Gain Control) amplifier 4. Then the reference data entering the A/D converter 5 is converted into a digital data therein and led to a data comparison section 6 under the control of the logic section 8. The data comparison section 6 compares the data with a data set in advance optionally and when dissidence beyond a prescribed range or over is detected, the section 6 issues a control signal to the AGC amplifier to correct the gain of the AGC amplifier 4 automatically. Thus, an accurate analog data is outputted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an analog data input circuit used in a data transmission system.

[Conventional technology]

Conventionally, in an analog data input circuit used in a data transmission system, as shown in FIG.
The analog data input from b or the reference data generated by the reference data generating section 2 are switched by the analog data switching section 3 and input to the A/D converter 5 via the amplifier 11. Then, it is converted into digital data by the A/D converter 5, and the digital data is outputted to the output terminal 10 via the logic section 8 and line interface section 9.

[Problem to be solved by the invention]

As mentioned above, in the conventional analog data input circuit in the data transmission system, the input analog data or reference data is input to the A/D converter via the amplifier, and is converted into digital data by the A/D converter 5 and output. Since the gain of the amplifier cannot be corrected because it is only transmitted to the output circuit, it has the disadvantage that erroneous digital data is transmitted to the output circuit, resulting in erroneous analog data being output.

An object of the present invention is to provide an analog data input circuit that can output accurate analog data.

[Means to solve the problem]

The analog data input circuit of the present invention includes a reference data generating section that generates data, an analog switching section that switches between the reference data generated by the reference data generating section and input analog data, and converting the analog data into digital data. An analog data input circuit configured to include an A/D converter for conversion, a buffer amplifier that performs automatic gain control of analog data output from the analog switching section and inputs it to the A/D converter; A/D
The configuration includes a data comparison section that compares the digital output of the reference data from the converter with an arbitrary set value and sends a control signal to the buffer amplifier when a discrepancy exceeding a predetermined range is detected.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

Referring to FIG. 1 showing one embodiment of the present invention, an analog data input circuit includes a reference data generation section 2 that generates data, an analog data switching section 3, and an AGC (Auto
aLic Ga1n Control; automatic gain control) amplifier 4, A/D converter 5, data comparison section 6,
It includes a buffer 7, a logic section 8, and a line interface section 9.

The operation will be explained below. Analog data is input terminal 1
input from analog data switching section 3 and A.
The signal is input to the A/D converter 5 via the GC amplifier 4. A
The analog data inputted to the /D converter 5 is converted into digital data, passed through the logic section 8, and then outputted to the line from the output terminal 10 through the line interface section 9.

On the other hand, the reference data is constantly generated in the reference data generation section 2, and is generated in the analog data switching section 3 under the control of the logic section 8.
is input to the A/D converter 5 via the AGC amplifier 4. The reference data input to the A/D converter 5 is converted into digital data and guided to the data comparison section 6 under the control of the logic section 8. The data comparison unit 6 compares this data with data arbitrarily set in advance, and if a discrepancy exceeding a predetermined range is detected, it sends out a control signal to automatically correct the gain of the AGC amplifier 4. do.

Although FIG. 1 shows an example in which the number of input terminals is two, this is not particularly limited.

〔Effect of the invention〕

As explained above, the present invention constantly compares digital data of A/D converted reference data with data arbitrarily set in advance in a data comparison section to detect the conversion accuracy of input analog data to digital data. Since the gain of the buffer amplifier is configured to be corrected, accurate analog data can be output.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram showing a conventional analog data input circuit. la, lb...input terminal, 2...reference data generation section, 3...analog data switching section,
4...AGC amplifier, 5...-A/D converter, 6...Data comparison section, 7...Buffer, 8...Logic section, 9... line interface section, 10... output terminal, 11...
···Amplifier.

Claims (1)

[Claims] a reference data generation section that generates data, an analog switching section that switches between the reference data generated by the reference data generation section and input analog data, and an A/D converter that converts the analog data into digital data. An analog data input circuit comprising: a buffer amplifier that performs automatic gain control of analog data output from the analog switching section and inputs it to the A/D converter; and a buffer amplifier that inputs the analog data from the A/D converter. An analog data input circuit comprising: a data comparison unit that compares a digital output of data with an arbitrary set value and sends a control signal to the buffer amplifier when a discrepancy exceeding a predetermined range is detected. .