KR920004814Y1 - Rf(radio frequency) automatic gain control circuit - Google Patents

Rf(radio frequency) automatic gain control circuit Download PDF

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Publication number
KR920004814Y1
KR920004814Y1 KR2019900012468U KR900012468U KR920004814Y1 KR 920004814 Y1 KR920004814 Y1 KR 920004814Y1 KR 2019900012468 U KR2019900012468 U KR 2019900012468U KR 900012468 U KR900012468 U KR 900012468U KR 920004814 Y1 KR920004814 Y1 KR 920004814Y1
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South Korea
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automatic gain
control circuit
gain control
filter
agc
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KR2019900012468U
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Korean (ko)
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KR920005551U (en
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김병일
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삼성전자 주식회사
김광호
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/44—Receiver circuitry for the reception of television signals according to analogue transmission standards
    • H04N5/52—Automatic gain control
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
    • H03K17/51—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used
    • H03K17/56—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices
    • H03K17/60—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices the devices being bipolar transistors
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/63—Generation or supply of power specially adapted for television receivers
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G2201/00—Indexing scheme relating to subclass H03G
    • H03G2201/30—Gain control characterized by the type of controlled signal
    • H03G2201/305—Gain control characterized by the type of controlled signal being intermediate frequency signal

Abstract

내용 없음.No content.

Description

RF자동이득제어회로RF automatic gain control circuit

제 1 도는 종래 RF자동이득제어회로를 나타낸 도면.1 is a diagram showing a conventional RF automatic gain control circuit.

제 2 도는 본 고안 RF자동이득제어회로의 블록구성도.2 is a block diagram of the RF automatic gain control circuit of the present invention.

제 3 도는 본 고안 RF자동이득제어회로의 상세회로도.3 is a detailed circuit diagram of the RF automatic gain control circuit of the present invention.

제 4 도는 제 3 도에 도시한 본 고안 RF자동이득제어회로의 입출력 신호파형도이다.4 is an input / output signal waveform diagram of the RF automatic gain control circuit of the present invention shown in FIG.

* 도면의 주요부분에 대한 부호의 설명* Explanation of symbols for main parts of the drawings

1 : 하이RF자동이득증폭기 2 : 로우RF자동이득증폭기1: High RF Automatic Gain Amplifier 2: Low RF Automatic Gain Amplifier

3 : 스위칭부3: switching unit

본 고안은 TV나 VTR등 영상기기의 RF자동이득제어회로(RF AGC)에 관한 것으로서, 특히 IC외부에 가변저항을 사용함이 없이 칩내부의 중간주파 자동이득제어회로필터의 전압만을 이용하여 RF신호의 레벨을 자동으로 조절하는 RF자동이득제어회로에 관한 것이다.The present invention relates to an RF automatic gain control circuit (RF AGC) of a video device such as a TV or a VTR, and in particular, an RF signal using only the voltage of the intermediate frequency automatic gain control circuit filter inside the chip without using a variable resistor outside the IC. The present invention relates to an RF automatic gain control circuit that automatically adjusts the level of?.

일반적으로 TV나 VTR등 영상기기에서는 영상신호의 강약에 따라 콘트래스트가 변화하게 되므로 그때마다 콘트래스트를 조정하지 않으면 안되는 문제가 있다. 이러한 문제를 해결하기 위해 고주파증폭회로나 중간주파증폭회로의 트랜지스터에 자동이득제어(AGC)전압을 가하여 영상신호가 강한 경우에는 증폭기의 증폭도를 내리고, 영상신호가 약하면 증폭도를 올려주게 된다. 그런데 종래의 RF자동이득제어회로(RF AGC)는 제 1 도에 도시한 바와같이 구성되어 있어서, IC외부에 존재하는 가변저항(VR)을 사용하여 가면저항(VR)의 저항값을 조절함으로서 RF신호의 레벨 즉, RF자동이득제어회로출력(RF AGC OUT)의 레벨 하이레벨 혹은 로우레벨전압으로 셋팅하도록 되어있다.In general, in a video device such as a TV or a VTR, the contrast changes according to the strength of the video signal, so there is a problem that the contrast must be adjusted each time. In order to solve this problem, an automatic gain control (AGC) voltage is applied to a transistor of a high frequency amplification circuit or an intermediate frequency amplification circuit to reduce the amplification of the amplifier when the image signal is strong, and to increase the amplification degree when the image signal is weak. However, the conventional RF automatic gain control circuit RF AGC is configured as shown in FIG. 1, and the resistance value of the mask resistance V R is adjusted by using the variable resistor V R existing outside the IC. By setting the level of the RF signal, that is, the level of the RF automatic gain control circuit output (RF AGC OUT) to the high or low level voltage.

따라서 RF신호의 레벨을 조절하기 위해서는 항상 TV나 VTR등 연상기기의 세트상에 설치된 조절기(가변저항)을 조절하여야만 하므로 사용상 매우 불편하다고 하는 결점이 있었다.Therefore, in order to adjust the level of the RF signal, it is necessary to adjust the regulator (variable resistor) installed on the set of the softener such as a TV or a VTR.

본 고안은 상기한 종래의 RF자동이득제어회로가 갖는 결점을 제거하고자 제안된 것으로, 하이RF자동이득제어증폭기와 로우RF자동이득제어증폭기를 이용하여 IC외부에 가변저항을 사용함이없이 RF신호의 레벨을 자동으로 조절하는 RF자동이득제어회로를 제공함에 그 목적이 있다.The present invention has been proposed to eliminate the drawbacks of the conventional RF automatic gain control circuit. The high RF automatic gain control amplifier and the low RF automatic gain control amplifier enable the RF signal to be removed without using a variable resistor outside the IC. The purpose is to provide an automatic RF gain control circuit that automatically adjusts the level.

이하 본 고안의 구성 및 작용, 효과를 첨부도면을 참조하여 상세하게 설명한다.Hereinafter, the configuration, operation, and effects of the present invention will be described in detail with reference to the accompanying drawings.

상기한 목적을 달성하기 위한 본 고안 RF자동이득제어회로는 중간주파자동이득제어회로필터의 전압(IF AGC Filter VTG)을 비반전단자(+)로 기준전압(Ref1)을 반전단자(-)로 각각 입력하여 중간주파자동이득제어회로필터의 전압(IF AGC Filter VTG)의 크기를 검출하는 하이RF자동이득증폭기(1)와, 상기 중간주파자동이득제어회로필터의 전압(IF AGC Filter VTG)을 반전단자(-)로 기준전압(Ref2)을 비반전단자(+)로 각각 입력하여 중간주파자동이득제어회로필터의 전압(IF AGC Filter VTG)의 크기를 검출하는 로우RF자동이득증폭기(2) 및 상기 하이, 로우 RF자동이득증폭기(1, 2)의 출력중 하나를 선택하여 RF자동이득제어회로의 출력(RF AGC OUT)으로서 출력하는 스위칭부(3)로 구성된다.The RF automatic gain control circuit of the present invention for achieving the above object has a voltage (IF AGC Filter VTG) of the intermediate frequency automatic gain control circuit filter as a non-inverting terminal (+) and a reference voltage (Ref 1 ) as an inverting terminal (-). A high RF automatic gain amplifier 1 for detecting the magnitude of the voltage of the intermediate frequency automatic gain control circuit filter (IF AGC Filter VTG) and a voltage of the intermediate frequency automatic gain control circuit filter (IF AGC Filter VTG) The low RF automatic gain amplifier which detects the magnitude of the IF AGC Filter VTG of the intermediate frequency automatic gain control circuit filter by inputting the reference voltage Ref 2 as the inverting terminal (-) to the non-inverting terminal (+), respectively. 2) and a switching unit 3 which selects one of the outputs of the high and low RF automatic gain amplifiers 1 and 2 and outputs it as an output of the RF automatic gain control circuit (RF AGC OUT).

제 2 도는 본 고안 RF자동이득제어회로의 블록구성도, 제 3 도는 본 고안 RF자동이득제어회로의 상세회로도, 제 4 도는 제 3 도에 도시한 본 고안 RF자동이득제어회로의 입출력신호파형도로서, 중간주파IC(IF IC)는 중간주파입력신호의 강약에 대해 내부 중간주파자동이득제어회로필터의 전압(IF AGC Filter VTG)을 충, 방전함에 의해 중간주파(IF) 또는 RF신호의 레벨을 제어하게 되는바, 본 고안은 하이RF자동이득증폭기(1)와 로우RF자동이득증폭기(2)을 이용하여 각각의 중간주파자동이득제어회로필터의 전압(IF AGC Filter VTG)에 대응되는 정보를 하이레벨 또는 로우레벨로 적절하게 셋팅시켜 출력하는 것이다.2 is a block diagram of the RF automatic gain control circuit of the present invention, FIG. 3 is a detailed circuit diagram of the RF automatic gain control circuit of the present invention, and FIG. 4 is an input / output signal waveform diagram of the RF automatic gain control circuit of the present invention shown in FIG. The intermediate frequency IC (IF IC) is a level of the intermediate frequency (IF) or RF signal by charging and discharging the voltage (IF AGC Filter VTG) of the internal intermediate frequency automatic gain control circuit filter against the strength of the intermediate frequency input signal. According to the present invention, the information corresponding to the voltage (IF AGC Filter VTG) of each intermediate frequency automatic gain control circuit filter using the high RF automatic gain amplifier (1) and the low RF automatic gain amplifier (2). Is set to high level or low level and output.

이와같은 작용을 하는 본 고안 RF자동이득제어회로의 동작을 제 3 도 및 제 4 도에 의거하여 구체적으로 설명하면 다음과 같다.The operation of the present invention RF automatic gain control circuit having such a function will be described in detail with reference to FIGS. 3 and 4 as follows.

제 4a 도에 도시한 중간주파자동이득제어회로필터의 전압(IF AGC Filter VTG)이 중간주파자동이득제어회로필터(IF AGC Filter)의 입력부(IP)에 있는 트랜지스터(Q1)의 베이스로 입력되면, 하이RF자동이득증폭기(1)에 있는 트랜지스터(Q4)와 로우RF자동이득증폭기(2)에 있는 트랜지스터(Q2)는 차동증폭기로서 동작하게 되므로 입력되는 중간주파자동이득제어회로필터의 전압(제 4a 도은 기준전압(Ref1, Ref2)과 동시에 비교되게 된다.The voltage IF AGC Filter VTG of the intermediate frequency automatic gain control circuit filter shown in FIG. 4A is input to the base of the transistor Q 1 in the input part IP of the IF AGC filter. If, in the high RF automatic gain transistors in the amplifier (1), (Q 4) and a low RF automatic gain intermediate frequency automatic gain control circuit filter transistor (Q 2) in the amplifier 2 is inputted so it operates as a differential amplifier The voltage (Fig. 4a is compared with the reference voltages Ref 1 , Ref 2 ) at the same time.

즉, 중간주파자동이득제어회로필터의 전압(IF AGC Filter VTG)이 기준전압(Ref1, Ref2))보다 높은 경우에는 트랜지스터(Q1)만이 턴온되고, 프랜지스터(Q2, Q4)는 턴오프되므로 트랜지스터(Q5, Q6)가 턴오프되어 스위칭부(3)에 있는 트랜지스터(Q7, Q8)도 턴오프된다.That is, when the voltage IF AGC Filter VTG of the intermediate frequency automatic gain control circuit filter is higher than the reference voltages Ref 1 and Ref 2 , only transistor Q 1 is turned on and transistors Q 2 and Q 4 . Since the transistor is turned off, the transistors Q 5 and Q 6 are turned off, and the transistors Q 7 and Q 8 in the switching unit 3 are also turned off.

따라서 스위칭부(3)로부터 출력되는 RF자동이득제어회로의 출력(RF AGC OUT)은 제 4b 도에 도시한 A구간과 같이 하이레벨신호로 된다.Therefore, the output (RF AGC OUT) of the RF automatic gain control circuit output from the switching section 3 becomes a high level signal as shown in section A shown in FIG. 4B.

또한 중간주파자동이득제어회로필터의 전압(IF AGC Filter VTG)이 기준전압(Ref1)보다 높고, 기준전압(Ref2)보다 낮으면, 트랜지스터(Q4)가 턴온되고, 트랜지스터(Q2)는 턴오프되므로 트랜지스터(Q5, Q6)가 각각 턴오프, 턴온되어 트랜지스터(Q6)의 컬렉터전류에 의해 스위칭부(3)에 있는 트랜지스터(Q7, Q8)가 각각 턴온 턴오프 된다.In addition, when the voltage IF AGC Filter VTG of the intermediate frequency automatic gain control circuit filter is higher than the reference voltage Ref 1 and lower than the reference voltage Ref 2 , the transistor Q 4 is turned on and the transistor Q 2 is turned on. It is because the turn-off transistor (Q 5, Q 6) are respectively turned off and is turned on and the transistor (Q 6) transistors (Q 7, Q 8) in the switching unit 3 by the collector current of that are respectively turned on and off .

그러므로 스위칭부(3)로부터의 출력되는 RF자동이득제어회로의 출력(RF AGC OUT)는 제 4b 도에 도시한 B구간과 같이 로우레벨로 된다.Therefore, the output (RF AGC OUT) of the RF automatic gain control circuit output from the switching section 3 is at a low level as in section B shown in FIG. 4B.

또 중간주파자동이득제어회로필터의 전압(IF AGC Filter VTG)이 기준전압(Ref1, Ref2)보다 낮은 경우에는 트랜지스터(Q2, Q4)가 모두 턴온되어 트랜지스터(Q5, Q6)가 턴온되므로 스위칭부(3)에 있는 트랜지스터(Q7, Q8)도 턴온된다.In addition, when the voltage (IF AGC Filter VTG) of the intermediate frequency automatic gain control circuit filter is lower than the reference voltages Ref 1 and Ref 2 , all the transistors Q 2 and Q 4 are turned on so that the transistors Q 5 and Q 6 . Since is turned on, the transistors Q 7 and Q 8 in the switching section 3 are also turned on.

그에 따라 스위칭부(3)로부터 출력되는 RF자동이득제어회로의 출력(RF AGC OUT)는 제 4c 도에 도시한 C구간과 같이 로우레벨로 된다.As a result, the output RF AGC OUT of the RF automatic gain control circuit output from the switching section 3 is at a low level as shown in section C of FIG. 4C.

따라서 IC외부가변저항에 의해 RF자동이득제어회로의 출력특성을 전압적으로 지연시킬 필요없이 기준전압(Ref)의 포인트를 더욱 세밀하게 확장시키면, 중간주파자동이득제어회로의 특성에 따른 하이레벨 또는 로우레벨의 RF자동이득제어회로의 특성을 신호레벨에 따라 자동적으로 얻을 수 있다.Therefore, if the point of the reference voltage (Ref) is extended more precisely without the need to delay the output characteristics of the RF automatic gain control circuit by the IC external resistance resistor, the high level or The characteristics of the low-level RF automatic gain control circuit can be automatically obtained according to the signal level.

이상과 같이 작용하는 본 고안은 IC외부에 가변저항을 사용함이 없이 칩내부의 중간주파자동이득제어회로필터의 전압만을 이용하여 RF신호의 레벨을 자동으로 조절하게 되므로 가변저항의 조절에 따른 불편함이 제거되어 사용상 매우 편리할 뿐만아니라 칩에 조절핀이 필요없게 되어 핀 하나를 줄일 수 있는 장점이 있다.The present invention, which operates as described above, automatically adjusts the level of the RF signal using only the voltage of the intermediate frequency automatic gain control circuit filter inside the chip without using a variable resistor outside the IC. This removal is not only very convenient for use but also eliminates the need for an adjustment pin on the chip, which has the advantage of reducing one pin.

Claims (4)

중간주파자동이득제어회로필터의 전압(IF AGC Filter VTG)을 비반전단자(+)로 기준전압(Ref1)을 반전단자(-)로 각각 입력하여 중간주파자동이득제어회로필터의 전압(IF AGC Filter VTG)의 크기를 검출하는 하이 RF자동이득증폭기(1)와 상기 중간주파자동이득제어회로필터의 전압(IF AGC Filter VTG)을 반전단자(-)로 기준전압(Ref2)을 비반전단자(+)로 각각 입력하여 중간 주파자동이득제어회로필터의 전압(IF AGC Filter VTG)의 크기를 검출하는 로우RF자동이득증폭기(2) 및 상기 하이, 로우RF자동이득증폭기(1, 2)의 출력중 하나를 선택하여 RF자동이득제어회로의 출력(RF AGC OUT)으로서 출력하는 스위칭부(3)로 구성된 RF자동이득제어회로.Input voltage (IF AGC Filter VTG) of intermediate frequency automatic gain control circuit filter to non-inverting terminal (+) and reference voltage (Ref 1 ) to inverting terminal (-) respectively. Non-inverting the reference voltage (Ref 2 ) with the high RF automatic gain amplifier (1) for detecting the magnitude of AGC Filter VTG) and the voltage (IF AGC Filter VTG) of the intermediate frequency automatic gain control circuit filter with the inverting terminal (-). Low RF automatic gain amplifiers (2) and the high and low RF automatic gain amplifiers (1, 2) respectively input to the terminal (+) to detect the magnitude of the voltage (IF AGC Filter VTG) of the intermediate frequency automatic gain control circuit filter. An RF automatic gain control circuit comprising a switching unit (3) which selects one of the outputs and outputs the RF automatic gain control circuit as an output (RF AGC OUT). 제 1 항에 있어서, 하이RF자동이득증폭기(1)가 저항(R1, R2)과 트랜지스터(Q4, Q6)로 구성된 RF자동이득제어회로.2. The RF automatic gain control circuit according to claim 1, wherein the high RF automatic gain amplifier (1) is composed of resistors (R 1 , R 2 ) and transistors (Q 4 , Q 6 ). 제 1 항에 있어서, 로우RF자동이득증폭기(2)가 저항(R3)과 트랜지스터(Q2, Q5)로 구성된 RF자동이득제어회로.2. The RF automatic gain control circuit according to claim 1, wherein the low RF automatic gain amplifier (2) is composed of a resistor (R 3 ) and a transistor (Q 2 , Q 5 ). 제 1 항에 있어서, 스위칭부(3)가 저항(R4)과 트랜지스터(Q7, Q8)로 구성된 RF자동이득제어회로.2. The RF automatic gain control circuit according to claim 1, wherein the switching section (3) comprises a resistor (R 4 ) and a transistor (Q 7 , Q 8 ).
KR2019900012468U 1990-08-18 1990-08-18 Rf(radio frequency) automatic gain control circuit KR920004814Y1 (en)

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KR2019900012468U KR920004814Y1 (en) 1990-08-18 1990-08-18 Rf(radio frequency) automatic gain control circuit

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KR2019900012468U KR920004814Y1 (en) 1990-08-18 1990-08-18 Rf(radio frequency) automatic gain control circuit

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KR920005551U KR920005551U (en) 1992-03-26
KR920004814Y1 true KR920004814Y1 (en) 1992-07-20

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