MAX9670CTL+ Maxim Integrated Products, MAX9670CTL+ Datasheet - Page 13

• Manufacturer Part Number: MAX9670CTL+
• Description: IC AUDIO/VIDEO SWIT DUAL 40TQFN
• Manufacturer: Maxim Integrated Products

Specifications of MAX9670CTL+

• Function: Audio/Video Switch
• Circuit: 2 x SCART
• Voltage Supply Source: Single Supply
• Voltage - Supply, Single/dual (±): 3.3 V ~ 12 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 40-WFQFN Exposed Pad
• For Use With: MAX9670EVKIT+ - EVALUATION KIT FOR MAX9670
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The MAX9670/MAX9671 represents Maxim’s third gen-
eration of SCART audio/video (A/V) switches. Under I
control, these devices route audio, video, and control
information 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, three-level signal that indicates
whether the picture aspect ratio is 4:3 or 16:9 or causes
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.
The low power consumption and the advanced monitor-
ing functions of the MAX9670/MAX9671 enable the cre-
MAX9670
28
29
30
31
32
33
34
35
36
37
38
39
40
—
Volume Control for Dual SCART Connectors
PIN
Low-Power Audio/Video Switch with Audio
MAX9671
31
32
33
34
35
36
37
38
39
40
41
42
43
—
______________________________________________________________________________________
Detailed Description
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
VCR_R/C_IN
ENC_R/C_IN
ENC_C_IN
ENC_Y_IN
GNDVID
NAME
V
EP
VID
Video Ground
VCR SCART Red/Chroma Video Input
Video and Digital Supply. Connect to a 3.3V supply. Bypass with parallel 1µF and
0.1µF ceramic capacitors to GNDVID. V
I
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.
2
C interface.
2
C
ation of lower power set-top boxes, televisions, and
DVD players. Unlike competing SCART ICs, the audio
and video circuits of the MAX9670/MAX9671 operate
entirely from 3.3V rather than from 5V and 12V. Only the
slow-switch circuit of the MAX9670/MAX9671 requires a
12V supply. The MAX9670/MAX9671 also have circuits
that detect activity on the CVBS inputs, loads on the
CVBS outputs, and the level of the slow-switch signals.
The INT signal informs the microcontroller if there are
any changes so that the microcontroller can intelli-
gently decide whether to power up or power down
the equipment.
In addition, the MAX9670/MAX9671 have DirectDrive
audio circuitry to eliminate click-and-pop noise. With
DirectDrive, the DC bias of the audio line outputs is
always at ground, no matter whether the MAX9670/
MAX9671 are being powered up or powered down.
Conventional audio line output drivers that operate from a
single supply require series AC-coupling capacitors.
During power-up, the DC bias on the AC-coupling capac-
itor moves from ground to a positive voltage, and during
power-down, the opposite occurs. The changing DC bias
usually causes an audible transient.
Pin Description (continued)
FUNCTION
VID
also serves as a digital supply for the
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