KR900008104Y1 - Oscilltor's local circuit of electronic tuner - Google Patents
Oscilltor's local circuit of electronic tuner Download PDFInfo
- Publication number
- KR900008104Y1 KR900008104Y1 KR2019880000815U KR880000815U KR900008104Y1 KR 900008104 Y1 KR900008104 Y1 KR 900008104Y1 KR 2019880000815 U KR2019880000815 U KR 2019880000815U KR 880000815 U KR880000815 U KR 880000815U KR 900008104 Y1 KR900008104 Y1 KR 900008104Y1
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- South Korea
- Prior art keywords
- uhf
- vhf
- osc
- pll
- oscillator
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Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03J—TUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS
- H03J7/00—Automatic frequency control; Automatic scanning over a band of frequencies
- H03J7/02—Automatic frequency control
- H03J7/04—Automatic frequency control where the frequency control is accomplished by varying the electrical characteristics of a non-mechanically adjustable element or where the nature of the frequency controlling element is not significant
- H03J7/06—Automatic frequency control where the frequency control is accomplished by varying the electrical characteristics of a non-mechanically adjustable element or where the nature of the frequency controlling element is not significant using counters or frequency dividers
- H03J7/065—Automatic frequency control where the frequency control is accomplished by varying the electrical characteristics of a non-mechanically adjustable element or where the nature of the frequency controlling element is not significant using counters or frequency dividers the counter or frequency divider being used in a phase locked loop
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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
- H04N5/50—Tuning indicators; Automatic tuning control
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- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Superheterodyne Receivers (AREA)
Abstract
내용 없음.No content.
Description
제 1 도는 본 고안의 회로가 포함된 전자식동조튜너의 회로계통도.1 is a circuit diagram of an electronic tuning tuner including a circuit of the present invention.
제 2 도는 종래의 회로도.2 is a conventional circuit diagram.
제 3 도는 본 고안과 종래회로와의 효과비교도.3 is a view comparing the effects of the present invention and the conventional circuit.
* 도면의 주요부분에 대한 부호의 설명* Explanation of symbols for main parts of the drawings
1 : 발진버퍼증폭부1: oscillation buffer amplifier
본 고안은 전자식 동조튜너의 국부출력타입에서의 발진기의 출력임피던스와 TV세트측의 PLL IG의 입력임피던스의 차이로 인한 특성의 불안정 및 품질의 신뢰성등을 개선하려는 전자식 동조튜너의 국부출력회로에 관한 것이다.The present invention relates to a local output circuit of an electronic tuning tuner to improve the instability of the characteristics and the reliability of the quality due to the difference in the output impedance of the oscillator in the local output type of the electronic tuning tuner and the input impedance of the PLL IG on the TV set side. will be.
일반적으로 전자식 동조튜너은 제 2 도와 같이 안테나로 부터 UHF의 밴드패스필너(BPF), 입력동조간, RF증폭기(RF AMP), 단간동조, 혼합기(MIX), UHF 발진기(UHF OSC), VHF 발진기(VHF OSC)의 계통으로 되고, 한편으로 VHF의 배드패스 필터(BPF), 입력동조간, RF 증폭기(RF AMP), 단간동조, 혼합기(MIX), IF 증폭기(IF AMP), IF 출력단(IF OUT) 측으로의 계통으로 이뤄져 있다.In general, the electronic tuning tuner is the UHF band pass filter (BPF), input tuning interval, RF amplifier (RF AMP), inter-step tuning, mixer (MIX), UHF oscillator (UHF OSC), and VHF oscillator VHF OSC), while VHF's bad pass filter (BPF), input tuning, RF amplifier (RF AMP), single tuning, mixer (MIX), IF amplifier (IF AMP), IF output stage (IF OUT) ) Is composed of the system to the side.
그러나, 상기 TV 세트측의 PLL IC로 발진기국부출력단을 거쳐 UHF 발진기(UHF OSC) 및 VHF 발진기(VHF OSC)의 출력이 가해질때는 상기 UHF, VHF 발진기(UHF, VHF OSC)의 발진출력레벨이 보통 85 dB이나, TV 세트측의 PLL IC 입력 감도는 적어도 83dB 이상으로 주어지므로, 튜너에서의 발진출력은 90dB 이상되야만 상기 PLL IC가 그 검출이 가능케 된다.However, when the output of the UHF oscillator (UHF OSC) and the VHF oscillator (VHF OSC) is applied via the oscillator local output stage to the PLL IC on the TV set side, the oscillation output levels of the UHF and VHF oscillators (UHF, VHF OSC) are usually Since the input sensitivity of the PLL IC on the TV set side is 85 dB or more, at least 83 dB, the oscillating output of the tuner must be 90 dB or more so that the PLL IC can detect it.
또, 이때는 튜너 출력에서 PLL IC 입력까지의 손실은 약 50dB정도 발생되고 있다.At this time, the loss from the tuner output to the PLL IC input is about 50dB.
그러므로, 상기와 같은 종래 기술에서는 튜너측에서의 발진출력과 PLL IC 입력측과의 입력감도가 불일치할 경우가 존재하므로서 그 특성이 불안정케 되고 회로의 신뢰성 저하를 야기시킨 것이었다.Therefore, in the prior art as described above, the oscillation output on the tuner side and the input sensitivity of the PLL IC input side are sometimes inconsistent, resulting in unstable characteristics and deterioration of the reliability of the circuit.
본 고안은 종래의 이러한 문제점을 제거하고자 안출한 것으로서, 이는 상기 튜너측의 발진기 국부 출력측과 TV 세트측의 PLL IC 입력측의 사이에 발진버퍼증폭부를 마련하므로서 이들 사이의 미스매칭(Miss Matching)에 따른 기기의 회로적 불안정을 해소할 목적이 있는 것이다.The present invention has been made to solve such a problem in the prior art, which provides an oscillation buffer amplifier between the oscillator local output side of the tuner side and the PLL IC input side of the TV set side, and according to the mismatch between them. The purpose is to resolve the circuit instability of the equipment.
이하에서 이를 좀더 구체적으로 설명하여 보면 다음과 같다.This will be described in more detail below.
즉, 본 고안은 제 1 도와 같이 UHF 발진기(UHF OSC) 및 VHF 발진기(VHF OSC)가 발진기 국부출력단측으로 이어지는 사이에서 발진버퍼 증폭부(1)를 연결하여서 된다.That is, the present invention is to connect the oscillation buffer amplifier 1 between the UHF oscillator (UHF OSC) and the VHF oscillator (VHF OSC) to the oscillator local output end side as shown in the first diagram.
상기 발진버퍼증폭부(1)는 발진증폭용 트랜지스터(Q)의 베이스 측으로 상기 UHF, VHF 발진기(UHF OSC, VHF OSC)의 출력이 각기 바이패스용 캐패시터(C1, C2)를 거쳐 공통 입력되고, 그 출력은 역시 바이패스 캐패시터(C4)를 거쳐 국부출력단으로 이어진다.The oscillation buffer amplifier 1 is a base of the oscillation amplifier transistor Q, and the outputs of the UHF and VHF oscillators UHF OSC and VHF OSC are respectively passed through a common capacitor C 1 and C 2 . The output is also connected to the local output stage via bypass capacitor C 4 .
미설명 부호 R1-R4는 바이어스 저항이다.Reference numerals R 1 -R 4 are bias resistors.
이러한 구성의 본 고안은 튜너측의 UHF 및 VHF 발진기(UHF OSC, VHF OSC)의 국부출력이 TV 세트측의 PLL IC 입력으로 전해질때 상기 발진버퍼증폭부(1)의 증폭용 트랜지스터(Q)로 소정레벨증폭되어 PLL IC로 인가된다.The present invention of such a configuration is directed to the amplifying transistor Q of the oscillation buffer amplifier 1 when the local outputs of the tuner side UHF and VHF oscillators (UHF OSC, VHF OSC) are delivered to the PLL IC input of the TV set side. A predetermined level is amplified and applied to the PLL IC.
그러므로 상기 발진기의 국부출력의 증폭도와 PLL IC의 입력 감도가 매칭이 되므로서 회로의 불안정성을 회복케 되어 그 신뢰성을 보장케 된다.Therefore, since the amplification of the local output of the oscillator and the input sensitivity of the PLL IC are matched, the instability of the circuit is restored and the reliability thereof is guaranteed.
또, 상기와 같은 본 고안에 의한 효과는 제 3 도와 같이 종래의 것과 본 고안을 비교하므로서 좀더 잘알 수 있게 된다.In addition, the effect of the present invention as described above can be better understood by comparing the present invention with the conventional one as the third degree.
이러한 본 고안은 튜너측의 발진기국부출력과 PLL IC의 입력 측에서의 임피던스 매칭이 양호히 이뤄짐에 의해 이러한 물품의 신뢰성 및 동작상의 안정성을 확보하게 되는 유익한 특징이 있는 것이다.The present invention is advantageous in that the oscillator local output on the tuner side and the impedance matching on the input side of the PLL IC are well achieved to secure reliability and operational stability of such an article.
Claims (1)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR2019880000815U KR900008104Y1 (en) | 1988-01-30 | 1988-01-30 | Oscilltor's local circuit of electronic tuner |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR2019880000815U KR900008104Y1 (en) | 1988-01-30 | 1988-01-30 | Oscilltor's local circuit of electronic tuner |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| KR890016795U KR890016795U (en) | 1989-08-19 |
| KR900008104Y1 true KR900008104Y1 (en) | 1990-09-03 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| KR2019880000815U KR900008104Y1 (en) | 1988-01-30 | 1988-01-30 | Oscilltor's local circuit of electronic tuner |
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| Country | Link |
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| KR (1) | KR900008104Y1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB9501243D0 (en) * | 1995-01-23 | 1995-03-15 | Rca Thomson Licensing Corp | Local oscillator using digital handswitching |
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1988
- 1988-01-30 KR KR2019880000815U patent/KR900008104Y1/en not_active IP Right Cessation
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| Publication number | Publication date |
|---|---|
| KR890016795U (en) | 1989-08-19 |
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