19-4040; Rev 0; 2/08
MAX7474 Evaluation Kit
General Description
The MAX7474 evaluation kit (EV kit) is a fully assem-
bled and tested printed-circuit board (PCB) that config-
ures the MAX7474 IC for automatically equalizing a
baseband composite video input signal from low-cost,
unshielded twisted pair (UTP) such as Category 5e
(Cat 5e) cable.
The MAX7474 EV kit operates from a single 5V DC
power supply. The EV kit accepts differential video
input signals and provides a single-ended output. The
EV kit features loss-of-sync and loss-of-burst outputs
and also provides an option to set the video output sig-
nal’s back-porch DC level.
♦
Differential Video Input
♦
Single-Ended AC- or DC-Coupled Output
♦
Fully Equalized for Up to 300m of Cat 5e Cable
♦
Improved Signal Quality for Up to 600m of Cat 5e
Cable
♦
Fixed Cable-Length Equalization in the Absence
of Burst
♦
Adjustable Back-Porch DC Level
♦
Loss-of-Burst (LOB) and Loss-of-Sync (LOS)
Outputs
♦
Evaluates the MAX7474 IC in 16-Pin SSOP
Package
♦
Fully Assembled and Tested
Features
♦
Single 5V DC Power-Supply Operation
Evaluates: MAX7474
Component Suppliers
SUPPLIER
AVX Corp.
KEMET Corp.
Murata Mfg. Co., Ltd.
PHONE
843-946-0238
864-963-6300
770-436-1300
WEBSITE
www.avxcorp.com
www.kemet.com
www.murata.com
PART
MAX7474EVKIT+
Ordering Information
TYPE
EV Kit
Note:
Indicate that you are using the MAX7474 when contacting
these component suppliers.
+Denotes
lead-free and RoHS-compliant.
Component List
DESIGNATION
BP_LVL, VOUT
C1, C2
QTY
2
2
DESCRIPTION
75Ω BNC PCB-mount connectors
1µF ±10%, 6.3V X5R ceramic
capacitors (0603)
Murata GRM188R60J105K
0.1µF ±10%, 16V X7R, ceramic
capacitors (0603)
Murata GRM188R71C104K
0.022µF ±10%, 50V X7R, ceramic
capacitors (0603)
Murata GRM188R71H223K
470µF ±20%, 6.3V tantalum
capacitor (D Case)
AVX TAJD477M006R
KEMET T491D477M006AT
PC test point, black
3-pin header
3-pin headers
DESIGNATION
JU4
R1, R2
R3
R4
QTY
1
2
1
1
DESCRIPTION
2-pin header
49.9Ω ±1% resistors (0603)
0Ω ±5% resistor (0603)
10kΩ ±10%, 3/8in square 19-turn
cermet trimmer
Twisted-pair adaptive video
equalizer (16-pin SSOP)
Maxim MAX7474EAE+
Low-power voltage reference
(5-pin SOT23)
Maxim MAX6037AAUK25+
RJ-45 black through-hole
connector, 8P-8C
PC test point, white
PC test point, red
Shunts
PCB: MAX7474 Evaluation Kit+
C3, C6
2
U1
1
C4, C5
2
U2
1
C7
1
VIN
V_INN
V_INP
—
—
1
1
1
4
1
GND
J1
JU1, JU2, JU3
1
1
3
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
MAX7474 Evaluation Kit
Evaluates: MAX7474
Quick Start
Required Equipment
Before beginning, the following equipment is needed:
• 5V, > 100mA DC power supply
• Video signal generator (e.g., Tektronix TG-700 or
equivalent)
• Video measurement equipment (e.g., Tektronix VM-
700T or equivalent)
• Active differential cable driver
The MAX7474 EV kit accepts differential video input
signals and provides a single-ended output nominal
1V
P-P
. A differential video input signal can be connect-
ed to the VIN RJ-45 connector (pins 7-8), or the V_INP
and V_INN test points on the MAX7474 EV kit. See
Table 4 in the
Jumper Selection
section for the VIN RJ-
45 connector pin configuration.
The MAX7474 EV kit automatically equalizes the base-
band composite video signal from a low-cost UTP cable,
and provides an option to set the fixed equalization
level to compensate for different input cable lengths up
to 300m in the absence of a burst signal. The MAX7474
fixed equalization level is jumper selectable. See the
Jumper Selection
section for more details.
The MAX7474 EV kit provides an option to set the
back-porch DC level for the video output signal. The
video output’s back-porch DC level can be set by an
on-board voltage reference (U2) or by an external volt-
age source connected to the BP_LVL BNC connector.
U2 is a MAX6037 voltage reference that provides an
on-board 0 to 2.5V voltage reference for the back-
porch DC level. Potentiometer R4 is used to set the
back-porch DC level. The back-porch DC level is set to
1.4V at the factory. See the
Jumper Selection
section
for more detail.
Procedure
The MAX7474 EV kit is fully assembled and tested.
Follow the steps below to verify board operation.
Caution: Do not turn on the power supply until all
connections are completed.
1) Install a shunt across pins 2-3 of jumper JU1 and a
shunt across pins 1-2 of jumper JU2 (for
≥
225m
manual cable length equalization).
2) Install a shunt across pins 1-2 of jumper JU3
(back-porch DC level set by R4).
3) Verify that no shunt is installed on jumper JU4 (AC-
coupled video output).
4) Connect the differential video input signal to the
VIN connector or the V_INP and VINN test points.
5) Connect the VOUT BNC connector on the EV kit to
the input of the video measurement equipment.
6) Connect the power-supply ground to the GND pad
on the EV kit.
7) Connect the 5V DC power supply to the VCC pad
on the EV kit.
8) Set the video signal generator for the desired video
input signal.
9) Turn on the power supply and enable the video
signal generator output.
10) Analyze the video output signal with the video
measurement equipment.
Jumper Selection
Fixed Equalization Level (FEQ0, FEQ1)
The MAX7474 EV kit provides an option to set the fixed
equalization level for the video input signal to compen-
sate for different cable lengths in the absence of burst.
Jumpers JU1 and JU2 set the fixed equalization level
pins (FEQ0 and FEQ1) of the MAX7474 IC. When using
cable lengths greater than 75m, set the fixed equaliza-
tion level according to Table 1.
Table 1. JU1 and JU2 Jumper Selection
(FEQ0, FEQ1)
SHUNT POSITION
JU2
(FEQ1)
2-3 (low)
2-3 (low)
1-2* (high)
1-2 (high)
JU1
(FEQ0)
2-3 (low)
1-2 (high)
2-3* (low)
1-2 (high)
EQUALIZATION
LEVEL (dB)
0
+4.5
+10.5
+10.5
COMPENSATED
CABLE
LENGTH (m)
0 to 75
75 to 225
≥
225
≥
225
Detailed Description of Hardware
The MAX7474 EV kit is designed to evaluate the
MAX7474 in a 16-pin SSOP package. The MAX7474 is
an adaptive equalizer for video over UTP cable. The EV
kit circuit is designed on a 2-layer, 1oz copper PCB
and all components are installed on the top layer. The
MAX7474 EV kit operates from a 5V DC power supply
that can deliver at least 100mA of current.
*Default
position.
2
_______________________________________________________________________________________
MAX7474 Evaluation Kit
Back-Porch DC Level (BPLVL)
The MAX7474 EV kit provides an option to set the
back-porch DC level for the video output signal.
Jumper JU3 selects the voltage source that sets the
back-porch DC level for the MAX7474 BPLVL pin. See
Table 2 for shunt positions.
RJ-45 Connector Pin Configuration (VIN)
The MAX7474 EV kit provides an RJ-45 connector to
accept a differential video input signal at the VIN RJ-
45 connector. Table 4 lists the RJ-45 connector pin
configuration.
Evaluates: MAX7474
Table 2. JU3 Jumper Selection (BPLVL)
SHUNT
POSITION
1-2*
MAX7474 BPLVL PIN
Connected to U2, pin 5
(through potentiometer
R4; 1.4V default)
Connected to BP_LVL
BNC connector
BACK-PORCH DC
LEVEL
0 to 2.5V (set by
potentiometer R4)
External reference
source
Table 4. RJ-45 Connector Pin
Configuration (VIN)
RJ-45 (VIN) PIN
1–6
7
8
SIGNAL
No connection
V_INN
V_INP
2-3
*Default
position.
Output Coupling (VOUT)
The MAX7474 EV kit provides an option to select the
output coupling of the video output signal on the
MAX7474 EV kit for AC- or DC-coupling. Jumper JU4
selects the output coupling for the MAX7474 output.
See Table 3 for shunt positions.
Header J1 (LOB, LOS)
The MAX7474 EV kit provides a 3-pin header to access
the LOB and LOS status output signals and GND. The
LOB outputs a logic-high when the color burst portion
of the video signal is not detected at the input.
Similarly, the LOS outputs a logic-high when the sync
signal of the video signal is not detected at the input.
Table 5 lists the header J1 pinout.
Table 3. JU4 Jumper Selection (VOUT)
SHUNT POSITION
Installed
Not installed*
MAX7474 OUTPUT
DC-coupled
AC-coupled
Table 5. Header J1 Pinout (LOB, LOS,
GND)
HEADER
J1 PIN
1
2
3
SIGNAL LEVEL
LOB = high
LOB = low
LOS = high
LOS = low
GND
FUNCTION
No color burst
Color burst detected
No sync signal
Sync signal detected
GND
*Default
position.
_______________________________________________________________________________________
3
MAX7474 Evaluation Kit
Evaluates: MAX7474
Figure 1. MAX7474 EV Kit Schematic
4
_______________________________________________________________________________________
MAX7474 Evaluation Kit
Evaluates: MAX7474
Figure 2. MAX7474 EV Kit Component Placement Guide—Component Side
Figure 3. MAX7474 EV Kit PCB Layout—Component Side
_______________________________________________________________________________________
5
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