Video - Sharp 70GS-61S Service Manual

70GS-61S
SYMBOL
−3 dB audio frequency bandwidth for
B
AF(−3dB)
FM
S/N weighted signal-to-noise ratio of
W(audio)
audio signal
α
AM suppression of FM demodulator
AM(sup)
PSRR power supply ripple rejection at pin 8 f
8(AM)
PSRR power supply ripple rejection at pin 8 f
8(FM)
V IF intercarrier level (RMS value),
o(rms)
valid also for radio
f frequency of reference signal at
ref
pin 15
V amplitude of reference signal source
ref(rms)
(RMS value)
Notes
1. Values of video and sound parameters can be decreased at V
2. Condition: luminance range (4 steps) 0 to 80%.
3. The sound carrier frequencies (depending on TV standard) are attenuated by the integrated sound carrier traps
(see Figs 16 to 21; H (s) is the absolute value of transfer function).
4. S/N is the ratio of black-to-white amplitude to the black level noise voltage (RMS value, pin 17). B = 5 MHz weighted
in accordance with "CCIR 567" .
5. The intercarrier output signal at pin 12 can be calculated by the following formula taking into account the internal
video signal with 1.1 V (p-p) as a reference:
V = 1.1 V (p-p)
o(intc)(rms)
where:
1
= correction term for RMS value,
---------- -
2 2
6 dB = correction term of internal circuitry and ±3 dB = tolerance of video output and intercarrier output amplitude
V .
o(intc)(rms)
6. The reference input pin 15 is able to operate as a 1-pin crystal oscillator as well as input terminal with external
reference signal, e.g. from the tuning system.
ICs ADITIONAL INFORMATION: TDA9886 (IC201)
PARAMETER
V
( )
i SC
( )
--------------- dB + 6 dB
V
( )
i PC
--------------------------------------------------------------- -
1
20
× ×
---------- - 10
2 2
V
( )
i SC
( )
--------------- dB
V
( )
i PC
CONDITIONS
without de-emphasis;
dependent on loop filter at
pin 4
27 kHz FM deviation;
50 µs de-emphasis;
vision carrier unmodulated
AM; m = 54%
50 µs de-emphasis;
AM: f = 1 kHz; m = 0.54
referenced to 27 kHz
FM deviation
= 70 Hz; see Fig.8
ripple
= 70 Hz; see Fig.8
ripple
QSS mode; SC ; sound
1
carrier 2 off
L standard; without
modulation
intercarrier mode; SC ;
1
sound carrier 2 off
note 6
operation as input terminal
= 4.75 V.
P
±
3 dB
= sound-to-picture carrier ratio at VIF input (pins 1 and 2) in dB,
22
MIN. TYP. MAX. UNIT
−
80 100 kHz
−
52 56 dB
−
45 50 dB
−
40 46 dB
−
20 26 dB
−
14 20 dB
90 140 180 mV
90 140 180 mV
− note 5 −
mV
− −
4 MHz
−
80 400 mV