U4935B Datasheet, PDF (11/16 Pages) TEMIC Semiconductors – SECAM Decoder

U4935B
SECAM Switch, Output Stage
The de-emphasis circuit provides the color-difference
signals which are blanked during the horizontal and
vertical blanking pulses. After blanking, the color
difference signals are switched every (B–Y) and (R–Y)
line by the SECAM switch.
The (B–Y) signal is then amplified 3.8 times and
available at Pin 10 after reversing. The (R–Y) signal is
amplified 2.54 times and available at Pin 9. When the
logic level at Pin 1 is “LOW”, the outputs have
high-impedance state.
Pin 15
SCP in
Pin 1
f_ref / ident
Pin 9
– (R–Y) out
Pin 10
– (B–Y) out
3.85 V
2.0 V
1.25 V
BGP : 3.85 V
HBLK : 2.0 V
VBLK : 1.25 V
f_ref = 4.433619 MHz
0.2 ~ 0.5 Vp–p
5.0 VDC at SECAM
1.5 VDC at no SECAM
Figure 20. Timing waveforms of the output stage
96 11718
TELEFUNKEN Semiconductors
Rev. A1, 28-Jan-97
Preliminary Information
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