akira CT-21XF9, Руководство по обслуживанию

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Model No: CT-21XF9A
Version 1.0
7. Introduction for IC TA1275Z
TA1275Z is the SECAM demodulation IC, which accomplishes a multicolor system with TB1231
series. This IC requires very few external parts.
Features
• Working with TB1231 series, which is PAL/NTSC PIF/VIF/VIDEO/CHROMA/DEF processor.
• Built-in FM demodulator with PLL circuit for color demodulation mad SECOM identification.
• DC voltage offset of demodulated signal adjuster.
• Input terminals for external R-Y/B-Y signals.
The pin functions and repair data of TA1275 is listed in the table 9. The inner structure block diagram
of TA1275 is show as figure 8.
Table 9 Pin functions and repair data of TA1275
Digital multimeter (GDM8145)
Resistance for GND
(Rx200KÙ)
Pin Symbol Function Quiescent
state (V) Dynamic
state (V)
Red pen
measure
Black
pen
measure
1 YOUT The output pin for Y signal.
Standard output level is
1.0Vp-p. The 5.5MHz trap
filter and delay line on the Y
signal processing is con-
trolled by the switch on pin
#2.
The output signal of the bell
filter can be monitored on
this pin by switching pin
#13 for testing.
1.18 2.24 3.0 2.9
2 MODESW The pin for controlling the
Y processing mode. to Vcc :
5.5MHz trap open: 5.5MHz
trap+DL to GND: DL
5.02 5.02 1.5 1.5
3 R-Y OUT The output pin for demodu-
lated R-Y signal. Standard
output level is 0.7Vp -p with
standard color bar signal. R-
Y processor has a LPF
to eliminate the carrier
components.
2.48 2.61 1.0 1.0
4 R-Y BLSCK
CONTOL
The pin for controlling the
black offset level. Adjusting
range is 30mV(This
pin should be opened in the
ease of using with TB 1231,
because TB 1231 has an IIC
BUS control for SECAM
black alignment)