E
MAX5003-50W Evaluation Kit
2
_______________________________________________________________________________________
Quick Start
The MAX5003 50W EV kit is fully assembled and tested.
The power supply has full isolation between the primary
and secondary circuit. A heatsink is included at the non-
component side for heatsinking the power MOSFET and
the output dual diode D4. During normal operation at full
output current, this heatsink becomes hot. A small fan
with direct airflow towards this heatsink is recommended
to keep the temperature rise to acceptable levels.
This power supply is not fused at the input. For
added protection, a 3A to 5A fuse should be used at
the input.
Appropriately sized heavy-gauge wires should be used
to connect the power supply to the EV kit and load.
Follow these steps to verify board operation.
Do not
turn on the power supply until all connections are
made.
1) Connect a 220μF bulk storage capacitor at the input
terminals of the EV kit. This capacitor should be
rated for 100V and be able to handle 1.5A of ripple
current.
2) Connect a +36V to +72V power supply to the pads
labeled VIN. The positive power-supply terminal
should connect to +V
IN
and the negative power-
supply terminal should connect to -V
IN
. The power
supply must be rated to at least 3A. The input volt-
age to the MAX5003 EV kit should not exceed 80V
at any time.
3) Connect a variable load capable of sinking at least
10A at 5V and a voltmeter to the pads labeled +V
O
and -V
O
.
4) Set the load current to approximately 5A.
5) Turn on the input power and verify that the output
voltage is +5V.
6) To evaluate the load regulation of the EV kit, vary
the load from 0 to 10A and record the output volt-
age variation as needed. For best measurement
accuracy, the voltmeter must be connected right to
the output pads of the EV kit.
7) To evaluate the line regulation of the EV kit, vary the
input voltage from +36V to +72V and record the
output voltage.
Note:
The MAX5003 EV kit undervoltage lockout circuit-
ry has been designed to shut down when the input sup-
ply voltage is under 32V.
Power Supply Typical
Specifications
Table 1 summarizes the typical performance of the 50W
power supply.
Table 1. Typical Specifications
Output Power
Input Voltage (V
IN
)
Output Voltage (V
OUT
)
Output Current (I
OUT
)
Initial Output Accuracy
Output Voltage Regulation
Efficiency
Input Output Isolation
SUPPLIER
PHONE
561-241-7876
402-564-3131
631-847-3000
310-322-3331
847-843-7500
201-392-7522
408-720-1440
FAX
Coiltronics
Dale-Vishay
General Semiconductor
International Rectifier
Nichicon
Panasonic
QT Optoelectronics
561-241-9339
402-563-6418
631-847-3236
310-322-3332
847-843-2798
201-392-4441
408-720-0848
DESIGNATOR
QTY
DESCRIPTION
U2
1
Optocoupler
QT Optoelectronics MOC217
Shunt regulator TL431AID
MAX5003ESE, 16-pin narrow SO
15V Zener diode
Panasonic MA8150
U3
U1
1
1
Z1
1
Component List (continued)
Component Suppliers
50W
±36V to ±72V
+5V
10A
±3%*
0.3%, over line and load
85% at 48V and 25W
1500V for 1s
Switching Topology
Feedforward Compensated
Forward Converter
Dimensions
*Initial setpoint accuracy can be improved by using tighter tol-
erance resistor divider (R11 and R12).
4.05in x 1.3in