參數(shù)資料
型號(hào): LA75691
元件分類: 接收器
英文描述: AM/FM, AUDIO/VIDEO DEMODULATOR, PDIP24
封裝: SDIP-24
文件頁(yè)數(shù): 12/13頁(yè)
文件大?。?/td> 206K
代理商: LA75691
No. 5734-8/13
LA75691
Continued from preceding page.
Pin No.
Pin
Function
Equivalent circuit
The VCC to ground decoupling capacitors must be placed as
close to the IC as possible.
5
VCC
Equalizer circuit. This circuit corrects the frequency
characteristics of the video signal.
Pin 17 is the equalizer amplifier input. A 1.5-V p-p signal is
input to pin 17, and that signal is amplified to be a 2-V p-p
signal by the equalizer amplifier.
Equalizer amplifier design:
The equalizer amplifier is designed as a voltage-follower
amplifier with a gain of about 2.3 dB. Connect an inductor, a
capacitor, and a resistor in series between pin 7 and ground
if the frequency characteristics require correction.
Notes on the equalizer amplifier:
If the input signal is vi and the output signal is vo, then:
R1
—— +1 (vi + vin) = Vo
× G
Z
G: The voltage-follower amplifier gain.
vin: Imaginary short
G: About 2.3 dB
Assuming that vin is 0, then:
VoG
R1
AV = ——— = —— +1
Vi
Z
R1 is the IC internal resistance of 1 k
. Simply select Z to
match the desired characteristics. However, note that Z must
be chosen carefully in order not to cause distortion, since the
equalizer amplifier gain will be maximum at the resonance
determined by Z.
6
7
8
EQ amp
PLL detector APC filter
The APC time constant is switched internally in the IC. When
locked, the VCO is controlled by loop A, and the gain is
reduced. When unlocked and in weak field reception, the
VCO is controlled by loop B, and the gain is increased.
For this APC filter the recommended values are:
R should be between 150 and 390
.
C should be 0.47 F.
9
APC FILTER
Continued on next page.
相關(guān)PDF資料
PDF描述
LA75693M AM/FM, AUDIO/VIDEO DEMODULATOR, PDSO24
LA75693VA FM, AUDIO/VIDEO DEMODULATOR, PDSO24
LA75694M AM/FM, AUDIO/VIDEO DEMODULATOR, PDSO24
LA75694M AM/FM, AUDIO/VIDEO DEMODULATOR, PDSO24
LA75695VA AM/FM, AUDIO/VIDEO DEMODULATOR, PDSO24
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LA75694M 制造商:SANYO 制造商全稱:Sanyo Semicon Device 功能描述:For Use in TV/VTR Applications IF Signal Processing (VIF/SIF for Hi-Fi)
LA75695VA 制造商:SANYO 制造商全稱:Sanyo Semicon Device 功能描述:For Use in TV/VTR Applications IF Signal Processing (VIF+SIF+SIF converter)
LA7570 制造商:SANYO 制造商全稱:Sanyo Semicon Device 功能描述:TV,VTR IF Signal Processor (Super Split PLL VIF+SIF)
LA75710VA 制造商:SANYO 制造商全稱:Sanyo Semicon Device 功能描述:Monolithic Linear IC NTSC Support TV and VCR VIF/SIF Signal Processing IC
LA7575 制造商:SANYO 制造商全稱:Sanyo Semicon Device 功能描述:Super-split, PLL-II Video and Sound IF Signal Processor