MAX9598 Maxim Integrated Products, MAX9598 Datasheet - Page 11

• Manufacturer Part Number: MAX9598
• Description: Low-Power Audio/Video Switch
• Manufacturer: Maxim Integrated Products

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1 SCART (from
ated 21-pin connector for connecting audio-visual equipment together. The official standard for SCART is CENELEC document num-
ber EN 50049-1. From Wikipedia.
The MAX9598 represents Maxim’s third generation of
SCART
these devices route audio, video, and control informa-
tion between the set-top box decoder chip and two
SCART connectors. The audio signals are left audio
and right audio. The video signals are composite video
with blanking and sync (CVBS) and component video
(red, green, blue). S-video (Y/C) can be transported
across the SCART interface if CVBS is reassigned to
luma (Y) and red is reassigned to chroma (C). Support
for S-video is optional. The slow-switch signal and the
fast-switch signal carry control information. The slow-
switch signal is a 12V, trilevel signal that indicates
whether the picture aspect ratio is 4:3 or 16:9 or caus-
es the television to use an internal A/V source such as
an antenna. The fast-switch signal indicates whether
the television should display CVBS or RGB signals.
CVBS, left audio, and right audio are full duplex. All the
other signals are half duplex. Therefore, one device on
the link must be designated as the transmitter and the
other device must be designated as the receiver.
PIN
EP
31
32
33
34
35
36
37
38
39
40
1
audio/video (A/V) switches. Under I
VCR_Y/CVBS_OUT VCR SCART Luma/Composite Video Output
TV_Y/CVBS_OUT
ENC_Y/CVBS_IN
VCR_Y/CVBS_IN
VCR_R/C_OUT
TV_Y/CVBS_IN
TV_R/C_OUT
ENC_R/C_IN
ENC_C_IN
ENC_Y_IN
Syndicat des Constructeurs d’Appareils Radiorécepteurs et Téléviseurs
NAME
EP
______________________________________________________________________________________
Detailed Description
Encoder Chroma Video Input
Encoder Red/Chroma Video Input
TV SCART Red/Chroma Video Output
VCR SCART Red/Chroma Video Output
TV SCART Luma/Composite Video Output
VCR SCART Luma/Composite Video Input
TV SCART Luma/Composite Video Input
Encoder Luma Video Input
Encoder Luma/Composite Video Input
Exposed Pad. The exposed pad is the internal ground for the audio amplifiers and charge pump. A
low-impedance connection between ground and EP is required for proper isolation.
Low-Power Audio/Video Switch for
2
C control,
Dual SCART Connectors
The low-power consumption and the advanced monitor-
ing functions of the MAX9598 enable the creation of
lower power set-top boxes, televisions, and DVD play-
ers. Unlike competing SCART ICs, the audio and video
circuits of the MAX9598 operate entirely from 3.3V rather
than from 5V and 12V. Only the slow-switch circuit of the
MAX9598 requires a 12V supply. The MAX9598 also has
circuits that detect activity on the CVBS inputs, loads on
the CVBS outputs, and the level of the slow-switch sig-
nals. The INT signal informs the µC if there are any
changes so that the µC can intelligently decide whether
to power up or power down the equipment.
In addition, the MAX9598 has DirectDrive audio circuit-
ry to eliminate click-and-pop noise. With DirectDrive,
the DC bias of the audio line outputs is always at
ground, no matter whether the MAX9598 is being pow-
ered up or powered down. Conventional audio line out-
put drivers that operate from a single supply require
series AC-coupling capacitors. During power-up, the
DC bias on the AC-coupling capacitor moves from
ground to a positive voltage, and during power-down,
the opposite occurs. The changing DC bias usually
causes an audible transient.
FUNCTION
Pin Description (continued)
) is a French-originated standard and associ-
11