Manual

MAX7446
4-Channel Video Filter for RGB and CVBS Video
4 _______________________________________________________________________________________
Pin Description
Detailed Description
The MAX7446 filters and buffers video-encoder DAC
outputs in applications such as set-top boxes, hard-
disk recorders, DVD players, and digital VCRs. The
MAX7446 reconstructs and cleans up analog video sig-
nals from the output of DAC video encoders. Each
channel consists of a lowpass filter and an output video
buffer that drives two standard 150Ω video loads.
The MAX7446 is designed to process CVBS, R, G, and
B video signals. The video signal processed by chan-
nel A (CVBS) must include a sync pulse. This sync
pulse provides the required timing to all four channels.
This device operates from a single +5V supply and has
a nominal cutoff frequency of 5MHz optimized for
NTSC, PAL, and SDTV.
SUPPLY CURRENT vs. TEMPERATURE
MAX7446 toc07
TEMPERATURE (°C)
SUPPLY CURRENT (mA)
603510-15
90
100
110
120
80
-40 85
INPUTS BIASED TO +2V
NO LOAD
DIFFERENTIAL GAIN
MAX7446 toc08
DIFFERENTIAL PHASE (DEGREES)
1st
3rd2nd 4th 5th
6th
1st
3rd2nd 4th 5th
6th
0.2
0.3
0.1
0
-0.1
-0.2
-0.3
DIFFERENTIAL GAIN (%)
0.2
0.3
0.1
0
-0.1
-0.2
-0.3
DIFFERENTIAL PHASE
MULTIBURST RESPONSE
MAX7446 toc09
10µs/div
250mV/div
250mV/div
IN_
OUT_
Typical Operating Characteristics (continued)
(V
CC
= +5V, T
A
= +25°C, unless otherwise noted.)
PIN NAME FUNCTION
1 INA C hannel A V i d eo Inp ut. U se channel A for the C V BS vi d eo si g nal . AC - coup l e IN A w i th a ser i es 0.1µF cap aci tor .
2 INB Channel B Video Input. Use channel B for the red (R) signal. AC-couple INB with a series 0.1µF capacitor.
3INC
Channel C Video Input. Use channel C for the green (G) (without sync) signal. AC-couple INC with a series
0.1µF capacitor.
4 IND Channel D Video Input. Use channel D for the blue (B) signal. AC-couple IND with a series 0.1µF capacitor.
5 DISABLE
Disable Logic Input. A logic-low on DISABLE enables the output buffers. A logic-high on DISABLE disables
all output buffers and puts them in a high-impedance state.
6–9 GND Ground
10 V
CC
+5V Supply Input
11 OUTD Channel D Video Output. This output can be either AC- or DC-coupled.
12 OUTC Channel C Video Output. This output can be either AC- or DC-coupled.
13 OUTB Channel B Video Output. This output can be either AC- or DC-coupled.
14 OUTA Channel A Video Output. This output can be either AC- or DC-coupled.