MAX7439ETP-T Maxim Integrated, MAX7439ETP-T Datasheet - Page 6

• Manufacturer Part Number: MAX7439ETP-T
• Description: Active Filter
• Manufacturer: Maxim Integrated

Specifications of MAX7439ETP-T

• Number Of Channels: 3
• Maximum Operating Temperature: + 85 C
• Package / Case: TQFN EP-20
• Minimum Operating Temperature: - 40 C

The MAX7438/MAX7439 reconstruction filters consist of
three separate lowpass filters with Butterworth-type
response. The filter features a maximally flat passband
for NTSC and PAL bandwidths, while maintaining good
group delay characteristics. The stopband offers excel-
lent attenuation at frequencies of 27MHz and above
(see the Typical Operating Characteristics section).
Triple-Channel Video Reconstruction Filters with
Back-Porch Clamp to GND
Table 1. External Resistor Values for Bypass Mode and High-Frequency Boost Control
6
11, 13, 15, 19
1, 4, 7, 10,
_______________________________________________________________________________________
No boost
Bypass
Boost 1
Boost 2
Boost 3
Boost 4
MODE
PIN
12
14
16
17
18
20
—
2
3
5
6
8
9
NAME
OUT1
OUT2
OUT3
HFB1
HFB3
HFB2
GND
V
V
EXT
IN1
IN3
IN2
R
EP
CC
SS
Open
HFB_-1
(kΩ)
11.3
16.5
11.3
4.42
15
Detailed Description
Ground
Channel 1 Video Input
Channel 1 High-Frequency Boost and Filter Bypass Control Input. Connect external resistors to HFB1
for high-frequency boost and filter bypass control. See Table 1.
Channel 1 Video Output
+5V Power Input
Channel 2 Video Output
-5V Power Input. Connect the backside exposed pad to V
Channel 3 Video Output
Channel 3 High-Frequency Boost and Filter Bypass Control Input. Connect external resistors to HFB3
for high-frequency boost and filter bypass control. See Table 1.
Channel 3 Video Input
Channel 2 High-Frequency Boost and Filter Bypass Control Input. Connect external resistors to HFB2
for high-frequency boost and filter bypass control. See Table 1.
Channel 2 Video Input
External Bias Resistor. Connect a 10kΩ resistor from EXT to GND.
Exposed Paddle. Connect to V
R
HFB_-2
(kΩ)
7.32
11.3
18.2
0
1
2
Filter Response
(V
V
HFB_
CC
0.318
0.758
4.027
1.53
Filter
2.5
0
= 5V)
(V)
SS
. Do not connect to GND.
The autotrimming circuit digitally controls the corner fre-
quency to maintain the frequency characteristics over
process and temperature.
The high-frequency boost compensates for signal
degradation and roll-off in the signal path prior to the
MAX7438/MAX7439 to increase image sharpness.
Program the level of high-frequency boost for each
channel by selecting the corresponding external resis-
tor values (R
Typical Operating Circuit section) given in Table 1. The
NOMINAL BOOST (dB)/
FUNCTION
(MAX7438)
BYPASS
Bypass
0.5
1.0
1.5
2.0
0
HFB_-1
SS
.
and R
HFB_-2
NOMINAL BOOST (dB)/
Pin Description
High-Frequency Boost
, as shown in the
(MAX7439)
BYPASS
Bypass
0.75
2.25
1.5
3.0
0