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.
Features
♦Single 5V DC Power-Supply Operation
♦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
Evaluates: MAX7474
MAX7474 Evaluation Kit
________________________________________________________________
Maxim Integrated Products
1
19-4040; Rev 0; 2/08
Component List
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.
Ordering Information
PART TYPE
MAX7474EVKIT+ EV Kit
+
Denotes lead-free and RoHS-compliant.
Component Suppliers
SUPPLIER PHONE WEBSITE
AVX Corp. 843-946-0238 www.avxcorp.com
KEMET Corp. 864-963-6300 www.kemet.com
Murata Mfg. Co., Ltd. 770-436-1300 www.murata.com
Note: Indicate that you are using the MAX7474 when contacting
these component suppliers.
DESIGNATION QTY DESCRIPTION
BP_LVL, VOUT 2 75Ω BNC PCB-mount connectors
C1, C2 2
1µF ±10%, 6.3V X5R ceramic
capacitors (0603)
Murata GRM188R60J105K
C3, C6 2
0.1µF ±10%, 16V X7R, ceramic
capacitors (0603)
Murata GRM188R71C104K
C4, C5 2
0.022µF ±10%, 50V X7R, ceramic
capacitors (0603)
Murata GRM188R71H223K
C7 1
470µF ±20%, 6.3V tantalum
capacitor (D Case)
AVX TAJD477M006R
KEMET T491D477M006AT
GND 1 PC test point, black
J1 1 3-pin header
JU1, JU2, JU3 3 3-pin headers
DESIGNATION QTY DESCRIPTION
JU4 1 2-pin header
R1, R2 2 49.9Ω ±1% resistors (0603)
R3 1 0Ω ±5% resistor (0603)
R4 1 10kΩ ±10%, 3/8in square 19-turn
cermet trimmer
U1 1
Twisted-pair adaptive video
equalizer (16-pin SSOP)
Maxim MAX7474EAE+
U2 1
Low-power voltage reference
(5-pin SOT23)
Maxim MAX6037AAUK25+
VIN 1 RJ-45 black through-hole
connector, 8P-8C
V_INN 1 PC test point, white
V_INP 1 PC test point, red
— 4 Shunts
— 1 PCB: MAX7474 Evaluation Kit+
Evaluates: MAX7474
MAX7474 Evaluation Kit
2 _______________________________________________________________________________________
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
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.
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.
The MAX7474 EV kit accepts differential video input
signals and provides a single-ended output nominal
1VP-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.
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)
JU1
(FEQ0)
EQUALIZATION
LEVEL (dB)
COMPENSATED
CABLE
LENGTH (m)
2-3 (low) 2-3 (low) 0 0 to 75
2-3 (low) 1-2 (high) +4.5 75 to 225
1-2* (high) 2-3* (low) +10.5 ≥ 225
1-2 (high) 1-2 (high) +10.5 ≥ 225
*
Default position.
Evaluates: MAX7474
MAX7474 Evaluation Kit
_______________________________________________________________________________________ 3
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.
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.
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.
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 2. JU3 Jumper Selection (BPLVL)
SHUNT
POSITION MAX7474 BPLVL PIN BACK-PORCH DC
LEVEL
1-2*
Connected to U2, pin 5
(through potentiometer
R4; 1.4V default)
0 to 2.5V (set by
potentiometer R4)
2-3 Connected to BP_LVL
BNC connector
External reference
source
*
Default position.
Table 5. Header J1 Pinout (LOB, LOS,
GND)
HEADER
J1 PIN SIGNAL LEVEL FUNCTION
LOB = high No color burst
1LOB = low Color burst detected
LOS = high No sync signal
2LOS = low Sync signal detected
3 GND GND
Table 3. JU4 Jumper Selection (VOUT)
SHUNT POSITION MAX7474 OUTPUT
Installed DC-coupled
Not installed* AC-coupled
*
Default position.
Table 4. RJ-45 Connector Pin
Configuration (VIN)
RJ-45 (VIN) PIN SIGNAL
1–6 No connection
7 V_INN
8 V_INP
Evaluates: MAX7474
MAX7474 Evaluation Kit
4 _______________________________________________________________________________________
Figure 1. MAX7474 EV Kit Schematic
Evaluates: MAX7474
MAX7474 Evaluation Kit
_______________________________________________________________________________________ 5
Figure 2. MAX7474 EV Kit Component Placement Guide—Component Side
Figure 3. MAX7474 EV Kit PCB Layout—Component Side
Evaluates: MAX7474
MAX7474 Evaluation Kit
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.
6
_____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2008 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc.
Figure 4. MAX7474 EV Kit PCB Layout—Solder Side
