ml6427 Fairchild Semiconductor, ml6427 Datasheet - Page 9

• Manufacturer Part Number: ml6427
• Description: 75w Quad Video Cable Drivers And Filters With Switchable Inputs
• Manufacturer: Fairchild Semiconductor

TYPICAL APPLICATIONS
USING THE ML6427 FOR PAL APPLICATIONS
The ML6427 can be optimized for PAL video by adding
frequency peaking to the composite and S-video outputs.
Figure 10 illustrates the use of an additional external
capacitor (330pF) in parallel with the output source
termination resistor. This raises the frequency response
from 1.6dB at 4.8MHz to 0.35dB at 4.8MHz, which
allows for accurate reproduction of the upper sideband of
the PAL subcarrier. Figure 11 shows the frequency
response of PAL video with various values of peaking
INPUTS
Bank A:
Bank B:
Other:
10
11
12
2
3
4
7
8
9
CHROMA IN
COMPOSITE
CV INU /Y1
CV INF A/Y2
CV INF B/Y3
R IN A/Y4
R IN B/Y5
G IN A/Y6
G IN B/Y7
B IN A/C1
B IN B/C2
RGB, CV filtered path
RGB, CV filtered path
CV unfiltered path, Sync IN (slave mode)
VIDEO IN
LUMA IN
SYNCIN
23
GNDO
Figure 5. EVC (Enhanced Video Connector) Application: S-Video, Composite, plus H-Sync out
19
SYNCOUT
GND
24
5
V CCO RGB
ML6427
10
11
12
A/B MUX
2
3
4
7
8
9
CV INU /Y1
CV INF A/Y2
CV INF B/Y3
R IN A/Y4
R IN B/Y5
G IN A/Y6
G IN B/Y7
B IN A/C1
B IN B/C2
17
1
SYNCIN
23
(Continued)
GNDO
V CCO CV
19
SWAP CVF SWAP CVU
22
13
Figure 4. Basic Application for NTSC
SYNCOUT
CV OUT 1/Y OUT A
CV OUT 2/Y OUT B
GND
24
G OUT /Y OUT D
R OUT /Y OUT C
5
B OUT /C OUT
V CC
6
14
MASTER
V CCO RGB
ML6427
A/B MUX
17
1
21
20
18
16
15
V CCO CV
SWAP CVF SWAP CVU
22
capacitors (220pF, 270pF, 330pF and none) between 0 and
10MHz.
For NTSC applications without the peaking capacitor the
rejection at 27MHz is 42dB (typical). For PAL applications
with the peaking capacitor the rejection at 27MHz is 38dB
(typical). See Figure 12. The differential group delay,
shown in Figure 13 with and without a peaking capacitor
(220pF, 270pF, and 330pF and none), varies slightly with
capacitance from 8ns to 13ns.
OUTPUTS
Option 1: 2 CV outputs + 2 TV modulator outputs, 1 RGB output
Option 2: 2 CV outputs + 1 TV modulator output, 1 S-video output
Other:
13
CV OUT 1/Y OUT A
CV OUT 2/Y OUT B
G OUT /Y OUT D
R OUT /Y OUT C
B OUT /C OUT
V CC
220µF
220µF
220µF
220µF
220µF
OPTIONAL FOR DC COUPLED APPLICATIONS
6
Sync output (buffered stripped sync)
14
75
75
75
75
75
21
20
18
16
15
CHROMA
LUMA
OUT
OUT
VIDEO CABLES
H SYNC OUT
COMPOSITE
VIDEO OUT
S-VIDEO
OUT
TO EVC
CONNECTOR
R/Y
G/Y
B/C
H SYNC OUT
CV/Y
MODULATOR
CV/Y
MODULATOR
ML6427
9