Datasheet
UEI25 Series
Single Output Isolated 25-Watt DC/DC Converters
MDC_UEI25W.B09 Page 1 of 24
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F1
External
DC 
Power
Source
Reference and
Error Amplifier
t4XJUDIJOH
t'JMUFST
t$VSSFOU4FOTF
-Vout (5)
+Vout (3)
Trim (4)
On/Off
Control
(6)
-Vin (2)
Open = On
$MPTFE0GG
+Vin (1)
1PTJUJWF
MPHJD
Controller
and Power
5SBOTGFS
*TPMBUJPO
Barrier
Typical topology is shown. Murata Power Solutions 
recommends an external fuse.
Typical unit
PRODUCT OVERVIEW
Featuring a full 25 Watt output in one square inch 
of board area, the UEI25 series isolated DC/DC 
converter family offers effi cient regulated DC power 
for printed circuit board mounting. The 0.96" x 1.1" 
x 0.32" (24.4 x 27.9 x 8.1 mm) converter accepts a 
2:1 input voltage range of 36 to 75 Volts DC, ideal 
for telecom equipment. The industry-standard pin-
out fi ts larger 1" x 2" converters. The fi xed output 
voltage is tightly regulated. Applications include 
small instruments, area-limited microcontrollers, 
data communications equipment, remote sensor 
systems, telephone equipment, vehicle and portable 
electronics.
The UEI25 series includes full magnetic and 
optical isolation with Basic protection up to 2250 
Volts DC. For powering digital systems, the outputs 
offer fast settling to step transients and will accept 
higher capacitive loads. Excellent ripple and noise 
specifi cations assure compatibility to noise-sus-
ceptible circuits. For systems requiring controlled 
startup/shutdown, an external remote On/Off control 
may use a switch, transistor or digital logic.
A wealth of self-protection features avoid both 
converter and external circuit faults. These include 
input undervoltage lockout and overtemperature 
shutdown. The outputs current limit using the 
“hiccup” autorestart technique and the outputs are 
short-circuit protected. Additional features include 
output overvoltage and reverse conduction elimina-
tion. The high effi ciency offers minimal heat buildup 
and “no fan” operation.
Figure 1. Connection Diagram
FEATURES
Cost effective small footprint DC/DC converter, 
ideal for high current applications
Industry standard 0.96" x 1.1" x 0.32" open 
frame package and pinout
Input voltage range of 36-75 Vdc
3.3V, 5V, or 12Vdc fi xed output voltages
Isolation up to 2250 VDC (basic)
Up to 25 Watts total output power with exten-
sive self-protection shutdown features
High effi ciency synchronous rectifi er forward 
topology up to 91%
Stable operation with no required external 
components
Usable -40 to 85°C temperature range (with 
derating)
Certifi ed to UL 60950-1, CAN/CSA-C22.2 No. 
60950-1, IEC60950-1, EN60950-1 safety 
approvals, 2nd edition
Output (V) Current (A) Nominal Input (V)
3.3 7.5 48
5548
12 2.1 48
REG.-Nr. D806










