KR920006004Y1 - Over-input detecting circuit - Google Patents

Abstract

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Description

Over input detection circuit

1 is a block diagram of the present invention.

2 is a detailed circuit diagram of the first and second level detectors 8 and 9 in FIG.

* Explanation of symbols for main parts of the drawings

1: Input unit 2: Input level adjusting unit

3: A / D converter 4: Digital signal processor

5: D / A conversion unit 6: Dolby unit

7: output unit 8: first level detector

9: second level detection unit 10: logic unit

11: level over display IC3: comparator

S1: switching part

The present invention relates to a digital processing circuit, and more particularly to a circuit for processing when an over-input or overflow occurs during digital processing.

In general, in the analog-to-digital converter (A / D), which converts an analog signal into a digital signal, the coding range of the digital signal is fixed.

Therefore, an overflow occurs when the input analog signal is larger than the designated encoding range, which is difficult to correct in a conventional circuit.

In addition, if an overflow occurs in the maximum significant bit (hereinafter referred to as MSB) during digital processing, it is difficult to correct it, and the digital-analog (Digital-Analog: hereinafter D) is not corrected. When converting, there is a disadvantage in that the output is distorted.

Therefore, the present invention provides a circuit capable of correcting an overflow when an A / D conversion and a digital processing of the present invention occur. Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram of the present invention. An input unit 1 which receives an analog signal An and outputs it in a stable state, and an input level which is useful for processing in the next stage by receiving an output of the input unit 1 is recognized. The output of the level adjusting section 2 for adjusting and outputting, the A / D converting section 3 for outputting the output of the level adjusting section 2 by A / D conversion, and the A / D converting section 3 The digital processing unit 4 outputs the data after the processing in the state and at the same time the overflow occurs, and the D / D converting the output processed by the digital processing unit 4 back to the original analog signal and outputting the same. A converting section 5, a switching section S1 for transmitting the output of the D / A converting section to line A or line B, and an input of the switching section S1 to line A. An output circuit 7 for outputting it when it is output or for outputting a predetermined Dolby circuit, and the line B of the switching unit S1. It receives the output and compresses the input level and increases the level on the output side to reduce the noise and outputs the Dolby unit 6 and the signal of the input line of the A / D converter 3, and the magnitude thereof is determined as the reference value. In comparison, a first level detector 8 for outputting a logic signal for a large and small signal, i.e., an overlevel signal, and a second level having the same function as the level detector 8 by receiving an input signal of the dolby part 6; The detection unit 9, the output signal of the first level detection unit 8, the output signal of the second level detection unit 9, and the digital signal processing unit 4 transmit an overlevel state to any one of the line D signals. Logic section 10 for outputting a logic for displaying the output if there is an output, and a level over display section 11 for displaying a level over the over-level state that is the output of the logic unit 10.

FIG. 2 is a detailed circuit diagram of the first and second level detectors 8 and 9 in the configuration of FIG. 1, which includes an amplifier 13 for amplifying an input signal and an output signal from the amplifier 13; A rectifying unit 14 for rectifying and outputting the rectified smoothly, and a comparator 15 for comparing the output signal of the rectifying unit 14 with a reference value Vrf and outputting a comparison state in logic.

The amplifying unit 13 is IC1, IC2, feedback resistors R1, VR1, signal resistor R2, coupling capacitor C1, and load resistor (Operational Amprifier). R3), the rectifier 14 includes a rectifier diode D1, a smoothing capacitor C2, and a load resistor R4, and the comparator 15 includes a comparator IC3 and a reference voltage source Vrf. do.

Hereinafter will be described a specific embodiment of the present invention that can realize the purpose of the above configuration.

In FIG. 1, the analog signal An is converted to an appropriate level by the level adjusting section 2 via the input section 1, and then input to the A / D converting section 3 to be converted into a digital signal, followed by a digital signal processing section ( 4) is entered.

The digital signal processing unit 4 is a sample of various types of systems for processing general digital signals, and when an overflow occurs during processing, the digital signal processing unit 4 outputs this signal to the line D and outputs the input signal by performing a predetermined process. do.

The digital data processed among the signals output from the digital signal processor 4 is converted into an analog signal again through the D / A converter 5 and is outputted by the switching unit S1 to the output unit 7 or the Dolby unit 6. Is entered. When the output signal of the D / A converter 5 is transmitted to the line A by the external operation of the user in the switching unit S1, the output unit 7 outputs the same, and the user D operates the D signal. When the output signal of the / A conversion unit 5 is connected to the line B, the noise is suppressed via the Dolby unit 6 and then input to the output unit 7, where the output unit 7 outputs the input signal. do.

At this time, the first level detector 8 detects, amplifies, smoothes the signal input to the A / D converter 2, and compares it with a reference value set in its own to output whether the level is over in a logic state. The second level detection unit 9 also detects the input signal of the Dolby unit 6, amplifies and smoothes it, and outputs whether or not the level is over in comparison with its set reference value in a logic state.

In addition, if any one of the outputs of the lines D of the first level detector 8, the second level over detector 9, and the digital signal processor 4 is in the level over or overflow state, the logic unit 10 Output this as logic. The level over display unit 11 receives the output of the logic unit 10 and displays it.

At this time, the user adjusts the level adjusting section 2 according to the state of the level over display section 11 so as to prevent the level overflow or overflow occurring in the circuit from the A / D converter 3 to the output circuit 7. You can turn it off.

In the first and second level detectors 8 and 9, when the input signal of the A / D converter 3 and the input signal of the Dolby unit 6 are input, the amplifiers IC1 and IC2 are input by the amplifier 13. After amplification by using the coupling capacitor (C1) and output through the load resistor (R3).

The rectifier 14 rectifies through the rectifying diode D1 when the output signal of the amplifier 13 is input and then smoothes through the smoothing capacitor C2 to output the load through the load resistor R4.

The output signal of the rectifier 14 is input to the comparator 15 to be compared with the reference value Vrf, and the comparator IC3 outputs the compared state. That is, it informs the overlevel state.

As can be seen from the above, the present invention displays the over-input level on the overflow or dolby part 6 generated by the over-input or digital conversion part 4 of the A / D conversion part, and the user displays the over-input level in the level display part 11. By adjusting the level of the level adjusting section 2, there is an advantage that a good output signal that is not crushed at the output can be obtained.

Claims (3)

In the over-input detection circuit, an input unit (1) for receiving an analog signal (An) and outputting it in a stable state, and for adjusting the level so as to receive the output of the input unit (1) and to be useful for processing in the next stage. Processing and outputting the level adjusting section 2, an A / D converting section 3 for outputting the output of the level adjusting section 2 by A / D conversion, and an output of the A / D converting section 3; At the same time, when the overflow occurs, the digital processing unit 4 for outputting it, the D / A conversion unit 5 for converting the output processed by the digital processing unit 4 back to an analog signal in its original state, and outputting it; A switching unit S1 for transmitting the output of the D / A conversion unit to a line A or line B, and an output of the switching unit S1 when the input of the switching unit S1 is transmitted to the line A, or a predetermined Dolby An output circuit 7 for outputting the output of the unit 6 and an output to the line B of the switching unit S1 The Dolby unit 6 which reduces noise and outputs the signal by compressing the above and increasing the level on the output side, and receiving the signal of the input line of the A / D conversion unit, comparing the magnitude with the reference value, A first level detector 8 for outputting an overlevel signal, a second level detector 9 having the same function as the level detector 8 by receiving an input signal from the dolby part 6, and the first When either the output signal of the level detection unit 8, the output signal of the second level detection unit 9, or the line D signal of the digital signal processing unit 4 has an output indicating an overflow or an overlevel state A logic section (10) for outputting logic indicating an overflow state or an overlevel state, and a level over display section (11) for displaying the output of said logic section. The amplifying unit 13 of claim 1, wherein the first and second level detectors 8 and 9 amplify and output the input signal, and a rectifying unit rectifying and outputting the output signal of the amplifying unit 13. 14) and a comparator (15) for outputting the compared state in logic when the output signal of the rectifier (14) is compared with a reference value. 2. The amplifier of claim 1, wherein the amplifier 13 comprises an op amp IC1, IC2, feedback resistors R1 and VR1, a signal resistor R2, a coupling capacitor CI and a load resistor R3. 14 is a rectifier diode D1, a smoothing capacitor C2, and a load resistor R4, and the comparator 15 is composed of a comparator IC3 and a reference value Vrf. .