MAX7452 Evaluation Kit
Evaluates: MAX7452
6) Connect the OUT BNC connector on the EV kit to
the input of the video measurement equipment.
7) Connect the power-supply ground to the GND pad.
8) Connect the +5V supply to the V
CC
pad on the EV kit.
9) Connect the negative terminal of the adjustable ref-
erence voltage to the GND pad.
10) Connect the positive terminal of the adjustable ref-
erence voltage to the BPLVL pad.
11) Set the adjustable reference voltage to 1.8V.
12) Set the video-signal generator for the desired video
input signal, such as multiburst sweep. This signal
must contain sync information (i.e., CVBS or Y).
13) Turn on the power supply and the adjustable refer-
ence voltage and enable the video-signal generator.
14) Analyze the video output signal with the VM-700A
video measurement equipment.
provided to apply a DC voltage that is used to set the
back-porch level. The back-porch clamp output level is
defined by the following equations:
GSET = 1 (gain = 2V/V)
V
BACKPORCHLEVEL
= V
BPLVL
GSET = 0 (gain = 1V/V)
V
BACKPORCHLEVEL
= V
BPLVL
/ 1.5
An LOS test point is also provided on the EV kit. The
LOS output is logic high when the sync signal is not
present, indicating a loss of signal on the input for
approximately 15 horizontal lines.
The video input channel on the MAX7452 EV kit is AC-
coupled, while the video output channel is DC-coupled.
Both the input termination and output series termination
can be configured with jumpers. The MAX7452 EV kit
operates from a single +5V power supply.
Jumper Selection
Input Termination
The MAX7452 EV kit features an option to terminate the
video input channel to 75Ω or unterminated. Jumper
JU1 selects the input termination on the MAX7452 EV
kit. Table 1 lists the selectable jumper options.
Detailed Description
The MAX7452 EV kit is a fully assembled and tested
surface-mount circuit board that contains a MAX7452.
The MAX7452 provides complete front-end video-signal
conditioning and is designed to improve the quality of
standard-definition video signals. The MAX7452 also
provides out-of-band noise filtering, LOS detection,
user-adjustable back-porch clamp, AGC, and an output
buffer with selectable gains of 0dB or +6dB.
The MAX7452 EV kit features an option to disable the
AGC by setting the logic level at the AGCD pin of the
MAX7452. The AGC adjusts the overall amplitude of the
output signal until the sync amplitude equals the stan-
dard level. When the AGC is enabled (AGCD = logic
low), the video input signal is set to 1V
P-P
and then fed
into the output buffer. When the AGC is disabled
(AGCD = logic high), the video input signal is fed into
the output buffer without any adjustment of the gain.
The output buffer amplifies the video signal with a gain
of 1V/V or 2V/V, according to the logic level at the GSET
pin of the MAX7452.
The MAX7452 EV kit has a feature to adjust the back-
porch level at the output. A BPLVL PC board pad is
Table 1. JU1 Jumper Selection
SHUNT POSITION
Installed (default)
Not installed
VIDEO INPUT SIGNAL
TERMINATION
75Ω
Unterminated
Output Termination
The MAX7452 EV kit features an option to series terminate
the video output channel to 75Ω or unterminated. Jumper
JU2 selects the output termination on the MAX7452 EV
kit. Table 2 lists the selectable jumper options.
Table 2. JU2 Jumper Selection
SHUNT POSITION
Installed
Not installed (default)
VIDEO OUTPUT SIGNAL
TERMINATION
Unterminated
75Ω
2
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