KR880006909A - Integrated circuit for digital information signal separation and digital synchronization signal separation included in composite video signal - Google Patents

Abstract

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Description

Integrated circuit for digital information signal separation and digital sync signal separation included in composite video signal

Since this is an open matter, no full text was included.

1 is a block diagram of an integrated circuit of the present invention.

2 is a detailed circuit diagram of the block diagram of FIG. 1 according to the present invention;

3 is an operational waveform diagram of each part of the concrete circuit diagram of FIG.

* Explanation of symbols for main parts of the drawings

1: Buffer circuit 2: Low frequency filter

3: sampling circuit 4: memory circuit

5: impedance buffer circuit 6: comparison circuit

7: first drive circuit 8: amplifier

9 resonant circuit 10 comparison voltage generating circuit

11: comparator 12: second drive circuit

13: constant voltage generating circuit

Claims (1)

An integrated circuit that separates a digital information signal and a digital synchronization signal included in a composite video signal, comprising: a buffer circuit for amplifying an input signal, an active low frequency filter 2 for removing a high frequency portion of an input signal, and A sampling circuit (3) for removing a portion of the low frequency synchronizing signal appearing in the filtered signal, a storage circuit (4) for storing the voltage output from the sampling circuit (3) as a comparison voltage, and the stored comparison voltage An impedance buffer circuit 5 for converting the voltage into a voltage of an appropriate level and maintaining the comparison voltage for a sampling period, a comparison circuit 6 for comparing the comparison voltage input from the memory circuit with data of a video signal; A first drive circuit (7) for outputting the compared signals as legitimate levels of data, and an amplification for amplifying a composite video signal for digital synchronization signal separation; 8, a resonant circuit 9 for selecting a synchronization signal of a specific frequency from the composite video signal, a comparison voltage generation circuit 10 for generating a comparison voltage for comparing the output of the resonant circuit, and the comparison voltage Comparator 11 for comparing the resonant output, second drive circuit 12 for outputting the compared output as a square wave of an appropriate level, resistors R ₃₀ , R ₃₁ , R ₃₂ and transistors A predetermined constant voltage is supplied to the comparators 6 and 11 by a constant current source consisting of Q ₄₇ ), Q ₅₃ , and Q ₅₄ , and a diode connected transistor Q ₄₅ , Q ₄₆ , and Q ₄₈ -Q ₅₂ . And a constant voltage generator circuit for supplying a constant voltage to the first and second drive circuits 7 and 12 by the voltage drop of the resistor R ₃₅ of the constant current circuit composed of the resistors R _{33 to} R ₃₅ and the transistor Q ₅₅ . 13) a circuit, characterized in that consisting of. ※ Note: The disclosure is based on the initial application.