MAX7445 Datasheet, PDF (1/8 Pages) Maxim Integrated Products – 4-Channel Video Reconstruction Filter

19-2948; Rev 0; 8/03
4-Channel Video Reconstruction Filter
General Description
The MAX7445 4-channel, buffered video reconstruction
filter is ideal for anti-aliasing and DAC-smoothing video
applications or wherever analog video is reconstructed
from a digital data stream (such as cable/satellite/ter-
restrial set-top boxes, DVD players, hard-disk recorders
(HDRs), and personal video recorders (PVRs)). This
device operates from a single +5V supply and has a
flat passband out to 5MHz with a stopband attenuation
of 43dB at 27MHz. This makes it ideal for use with
NTSC, PAL, and standard-definition digital TV (SDTV)
video systems. Each output is capable of driving two
standard 150Ω video loads.
The MAX7445 has three modes of operation. Mode 1
processes CVBS and RGB video signals. Mode 2
processes CVBS, Y, and C signals, as well as a second
asynchronous CVBS video signal. Mode 3 processes
RGB and CVBS (asynchronous) video signals. An exter-
nal pin adjusts the gain of the video buffer to either +6dB,
+9.5dB, or +12dB to accommodate video-encoder DAC
output signals of <1V. High-frequency boost circuitry pro-
vides picture sharpness with +1.2dB of gain boost with-
out degradation in the stopband. The output video drivers
can be disabled with an external pin.
The MAX7445 is available in a 14-pin TSSOP package
with an exposed pad, and is specified over the -40°C to
+85°C extended temperature range.
Applications
Set-Top Boxes/HDRs
DVD Players
Game Consoles
Digital VCRs
Desktop Video Editors
ENCODER
D/A
0.1µF
INA
LOWPASS
FILTER
VCC
SYNC
DETECTOR
0.1µF
D/A
INB LOWPASS
FILTER
0.1µF
D/A
INC LOWPASS
FILTER
Features
o 4-Channel Filter and Buffer for CVBS, RGB, or Y/C
Video Signals
o Filter Response Ideal for NTSC, PAL, and
Interlaced SDTV Video Signals
o 43dB (typ) Stopband Attenuation at 27MHz
o ±0.75dB (max) Passband Ripple Out to 5MHz
o Blanking Level Voltage on Cable <1V
o Each Channel Drives Two 150Ω Video Loads
o +5V Single-Supply Voltage
o Selectable Gain: +6dB, +9.5dB, and +12dB
o Small 14-Pin TSSOP Package
Ordering Information
PART
MAX7445EUD
*EP = Exposed pad.
TEMP RANGE
-40°C to +85°C
PIN-PACKAGE
14 TSSOP-EP*
Pin Configuration appears at end of data sheet.
75Ω
*
OUTA
75Ω
*
75Ω
*
OUTB
75Ω
*
75Ω
*
OUTC
75Ω
*
Functional Diagram
75Ω
75Ω
75Ω
75Ω
75Ω
75Ω
SELECT
MAX7445
75Ω
75Ω
0.1µF
*
D/A
IND _LOWPASS
FILTER
SYNC
DETECTOR
OUTD
75Ω
75Ω
*
GND
DISABLE GAIN
*OPTIONAL CAPACITORS
________________________________________________________________ Maxim Integrated Products 1
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