max9508atet Maxim Integrated Products, Inc., max9508atet Datasheet - Page 13

• Manufacturer Part Number: max9508atet
• Description: Max9508 Video Filter Amplifier With Smartsleep And Bidirectional Video Support
• Manufacturer: Maxim Integrated Products, Inc.

If a load is connected to an output, the corresponding
filter and amplifier turn on and remain on until the out-
put load is disconnected. In full-operation mode,
SmartSleep intelligently reduces the supply current
based on the input signal presence and output loading.
Figures 4, 5, and 6 show which portions of the
MAX9508 turn on and which remain off with different
load configurations.
When an amplifier is on, it continually checks if the load
has been disconnected by detecting if the amplifier
Figure
4. Full-Operation Mode with CVBSOUT1 Loaded
VIDEO ENCODER
CURRENT
CURRENT
CURRENT
50mV
DAC
DAC
DAC
TO
VIDEO SIGNAL
0
PRESENT
______________________________________________________________________________________
SmartSleep and Bidirectional Video Support
+3.3V
+3.3V
SMARTSLEEP
EXTCVBSIN
INT/EXT
CVBSIN
Full-Operation Mode
SHDN
CIN
YIN
CVBS/S-Video Filter Amplifier with
CLAMP
OFF
OUTPUT LOAD CURRENT
BUFFER
BUFFER
ACTIVE VIDEO
OFF
OFF
2.9mA QUIESCENT
SUPPLY CURRENT
CONTROL
DETECT
LOGIC
BUFFER
PLUS
LPF
LPF
LPF
OFF
OFF
MAX9508
+3.3V
output is sourcing current during a horizontal line time.
If no sourcing current is detected within one horizontal
line time (approximately 64µs), the load has been dis-
connected and the amplifier returns to active-detect
mode. If, at any time, the input video signal is removed,
the MAX9508 returns to standby mode.
If the SmartSleep feature is not activated and the part is
not in shutdown, the filters and amplifiers completely
turn on, regardless of whether there is a video signal at
the CVBSIN input and whether there are loads connect-
ed at the outputs.
V
GND
DD
6dB
6dB
6dB
6dB
OFF
OFF
OFF
LOAD SENSE
LOAD SENSE
LOAD SENSE
LOAD SENSE
YOUT
CVBSOUT1
COUT
CVBSOUT2
75Ω
75Ω
75Ω
75Ω
CVBS1
SVIDEO
CHROMA
SVIDEO
LUMA
CVBS 2
75Ω
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