Ultralow Power SD Video Filter
with Load Detection
ADA4431-1
PIN CONFIGURATION
FEATURES
Third-order, low-pass video filter
1 dB flatness out to 6 MHz
27 dB rejection at 27 MHz
Low quiescent current: 4.7 mA typical
Low power-down current: 24 μA typical
Load detection capability
+V
1
2
3
4
12 GND
SUBS
S
LOAD
DETECT
IN
DIS
11
10 +V
G = 2
LPF
SAG correction
S
Allows use of smaller capacitors in ac-coupled outputs
Low supply voltage: 2.5 V to 3.6 V
Charge pump
9
CAP1
LDO
CHARGE PUMP
Creates a negative voltage from single positive supply
Allows capless output coupling with no dc offset
Rail-to-rail output
High input-to-output isolation in disabled state
89 dB @ 1 MHz
Figure 1.
+V
S
Small package
3 mm × 3 mm LFCSP
Low 0.55 mm package height
Wide operating temperature range: −40°C to +85°C
0.1µF
10
+V
0.1µF
1
16
4
+V
S
S
FB1
FB2
LDO
DIS
SYSTEM
CONTROLLER
3
15
ADA4431-1
VIDEO
OUT
VIDEO
DAC/
ENCODER
2
14 75Ω
OUT
SAG
IN
APPLICATIONS
x1
x2
LPF
Portable media players
Portable gaming consoles
Cell phones
Digital still cameras
Portable DVD players
Portable video cameras
13
7
GND
CAP4 CAP3 CAP2 CAP1 SUBS GND
11 12
5
6
8
9
0.1µF
0.1µF
1.0µF
Figure 2. Typical Application Circuit
GENERAL DESCRIPTION
The ADA4431-1 is a fully integrated video reconstruction filter
that combines excellent video specifications with low power
consumption, making it ideal for portable video filtering
applications. The ADA4431-1 is able to detect whether a video
load is present at the output, powering down the device when
the load is disconnected.
When operating with the charge pump off, the ADA4431-1
provides a dc offset to keep the sync tip approximately 100 mV
above ground. In addition, the part features SAG correction,
which permits the use of smaller capacitors in applications with
ac-coupled outputs.
The ADA4431-1 is packaged in a low profile 16-lead LFCSP and
operates in the industrial temperature range of −40°C to +85°C.
The ADA4431-1 operates on single supplies as low as 2.5 V
while providing the dynamic range required by the most
demanding video systems. The on-board charge pump
provides a virtual negative supply, allowing the video signal to
be dc-coupled and the black level to be set to ground, while the
sync passes cleanly at 300 mV below ground.
Rev. 0
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