MAX9598_09 Datasheet, PDF (26/36 Pages) Maxim Integrated Products – Low-Power Audio/Video Switch for Dual SCART Connectors

Low-Power Audio/Video Switch for
Dual SCART Connectors
311V connected through less than 0.1Ω to a signal pin.
The MAX9598 is soldered on the PCB when it experi-
ences such a discharge. Therefore, the current spike
flows through both external and internal ESD protection
devices and is absorbed by the supply bypass capaci-
tors, which have high capacitance and low ESR.
To better protect the MAX9598 against excess voltages
during the cable discharge condition or ESD events, add
series resistors to all inputs and outputs to the SCART
connector if series resistors are not already present in
the application circuit. Also add external ESD protection
diodes (for example, BAV99) on all inputs and outputs to
the SCART connector.
Power-Supply Bypassing
The MAX9598 features single 3.3V and 12V supply
operation and requires no negative supply. The 12V
supply, V12 is for the SCART switching function. For
V12, place a 0.1µF bypass capacitor as close as possi-
ble. Connect all VAUD pins together to 3.3V and bypass
with a 10µF electrolytic capacitor in parallel with a 0.1µF
ceramic capacitor to audio ground. Bypass each VVID
to video ground with a 0.1µF ceramic capacitor.
Using a Digital Supply
The MAX9598 was designed to operate from noisy digital
supplies. The high PSRR (49dB at 100kHz) allows the
MAX9598 to reject the noise from the digital power sup-
plies (see the Typical Operating Characteristics). If the
digital power supply is very noisy and stripes appear on
the television screen, increase the supply bypass capaci-
tance. An additional, smaller capacitor in parallel with the
main bypass capacitor can reduce digital supply noise
because the smaller capacitor has lower equivalent series
resistance (ESR) and equivalent series inductance (ESL).
Layout and Grounding
For optimal performance, use controlled-impedance
traces for video signal paths and place input termina-
tion resistors and output back-termination resistors
Table 8. Data Format for Write Mode
REGISTER
ADDRESS
(HEXADECIMAL)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
00h
Not used
ZCD
Not used
TV audio
output
mute
01h
Not used Not used Not used
Interrupt
VCR audio selection
TV audio selection
enable
02h
Not used
03h
Not used
04h
Not used
05h
Not used
06h
Not used
Not used
TV G and B video switch
TV video switch
07h
Not used Not used Not used
Set TV fast switching
Not used Set TV slow switching
08h
VCR_R/C_IN
Clamp
Not used
Not used
Not used
ENC_R/C_IN
clamp
VCR video switch
09h
Not used Not used Not used Not used
Not used
VCR_R/C_
Set VCR slow
OUT ground
switching
0Ah
Not used
0Bh
Not used
0Ch
Not used
0Dh
VCR_Y/CV
BS_OUT
enable
VCR_R/C_
OUT
enable
TV_R/C_
OUT enable
TV_G_OUT
enable
TV_B_OUT TV_Y/CVBS_ TVOUT_FS _{Not used}
enable OUT enable enable
10h
Operating mode
Not used
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