MAXIM MAX7452

19-3429; Rev 0; 9/04
MAX7452 Evaluation Kit
The MAX7452 evaluation kit (EV kit) is a fully assembled
and tested surface-mount circuit board that contains
the MAX7452. The MAX7452 is a low-cost, high-performance, complete front-end video-signal conditioner
with automatic gain control (AGC) and a useradjustable back-porch clamp. The device includes an
out-of-band noise filter, back-porch clamp, loss-of-sync
(LOS) detector, ±6dB of AGC, and an output buffer
capable of driving either a 150Ω video load or a highimpedance load. These features optimize the video
signal quality for further video processing through a
crosspoint device or video decoder. The EV kit operates from a single +5V power supply.
Features
♦ Single +5V Supply Operation
♦ Adjustable Back-Porch Clamp
♦ Output Buffer Drives Standard Video Load
♦ Jumper-Selectable Output Buffer Gain of 0dB or
+6dB
♦ Input Fault Detection with LOS Output
♦ AGC (±6dB Range)
♦ Jumper-Selectable AGC Enable/Disable
♦ Standard 75Ω Input/Output Termination
♦ Jumper-Selectable Input/Output Termination
♦ Surface-Mount Components
♦ Fully Assembled and Tested
Component List
DESIGNATION
QTY
C1
1
1µF ±10%, 10V X5R ceramic
capacitor (0603)
TDK C1608X5R1A105K
2
0.1µF ±10%, 25V X7R ceramic
capacitors (0603)
TDK C1608X7R1E104K
C2, C3
DESCRIPTION
IN, OUT
2
75Ω PC board mount BNC
connectors
JU1, JU2
2
2-pin headers
JU3, JU4
2
3-pin headers
R1, R2
2
75Ω ±1% resistors (0805)
U1
1
MAX7452ESA (8-pin SO-EP)
—
4
Shunts
—
1
MAX7452 PC board
Component Suppliers
SUPPLIER
TDK
PHONE
FAX
847-803-6100 847-390-4405
WEBSITE
www.component
.tdk.com
Note: Indicate that you are using the MAX7452 EV kit when
contacting this supplier.
Ordering Information
PART
TEMP RANGE
MAX7452EVKIT
0°C to +70°C
IC PACKAGE
8 SO-EP*
*EP = Exposed paddle.
Quick Start
Recommended Equipment
• +5VDC power supply
• Adjustable reference voltage (1V to 3V) or power supply
• Video-signal generator (e.g., Tektronix TG-2000)
• Video measurement equipment (e.g., Tektronix VM700A)
Procedure
The MAX7452 EV kit is fully assembled and tested.
Follow these steps to verify board operation. Do not
turn on the power supply until all connections are
completed:
1) Verify that a shunt is installed across jumper JU1
(75Ω input termination).
2) Verify that a shunt is not installed across jumper
JU2 (75Ω output series termination).
3) Verify that a shunt is installed across pins 1 and 2 of
jumper JU3 (gain = 2).
4) Verify that a shunt is installed across pins 2 and 3 of
jumper JU4 (AGC enabled).
5) Connect the output of the video-signal generator to
the IN BNC connector on the MAX7452 EV kit.
________________________________________________________________ Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
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Evaluates: MAX7452
General Description
Evaluates: MAX7452
MAX7452 Evaluation Kit
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 VCC pad on the EV kit.
9) Connect the negative terminal of the adjustable reference voltage to the GND pad.
10) Connect the positive terminal of the adjustable reference 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 reference voltage and enable the video-signal generator.
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)
VBACKPORCHLEVEL = VBPLVL
GSET = 0 (gain = 1V/V)
VBACKPORCHLEVEL = VBPLVL / 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 ACcoupled, 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.
14) Analyze the video output signal with the VM-700A
video measurement equipment.
Jumper Selection
Detailed Description
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.
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 standard level. When the AGC is enabled (AGCD = logic
low), the video input signal is set to 1VP-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 backporch level at the output. A BPLVL PC board pad is
2
Input Termination
Table 1. JU1 Jumper Selection
SHUNT POSITION
VIDEO INPUT SIGNAL
TERMINATION
Installed (default)
75Ω
Not installed
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
VIDEO OUTPUT SIGNAL
TERMINATION
Installed
Unterminated
Not installed (default)
75Ω
_______________________________________________________________________________________
MAX7452 Evaluation Kit
Evaluates: MAX7452
AGC and Output Buffer Gain Selection
Table 3. JU3 and JU4 Jumper Selection
The MAX7452 EV kit features an option to select the
AGC and output buffer gain. Jumper JU4 (AGCD) controls the AGC enable and disable, while jumper JU3
(GSET) sets the output buffer gain. Table 3 lists the
selectable jumper options.
SHUNT POSITION
VOUT
JU3 (GSET)
JU4 (AGCD)
2 and 3 (low)
2 and 3 (low)
1VP-P fixed
1 and 2 (high)
2 and 3 (low)
2VP-P fixed (default)
2 and 3 (low)
1 and 2 (high)
VOUT = VIN
1 and 2 (high)
1 and 2 (high)
VOUT = 2VIN
VCC
VCC
GND
1
C1
1µF
LOS
VCC
LOS
8
C2
0.1µF
VCC
IN
2
JU1
R1
75Ω
1%
IN
C3
0.1µF
U1
GSET
7
1
JU3
2
3
MAX7452
3
GND
GSET
OUT
6
R2
75Ω
1%
OUT
VCC
BPLVL
4
BPLVL
AGCD
5
JU4
1
JU2
AGCD
2
3
Figure 1. MAX7452 EV Kit Schematic
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Evaluates: MAX7452
MAX7452 Evaluation Kit
Figure 2. MAX7452 EV Kit Component Placement Guide—
Component Side
Figure 3. MAX7452 EV Kit PC Board Layout—Component Side
Figure 4. MAX7452 EV Kit PC Board Layout—Solder Side
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
4 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2004 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.