Datasheet
Fabricated on a 0.41 by 0.65 inch (10.4 by 16.5
mm) Single Inline Package (SIP) module, the OKI-
78SR series are non-isolated switching regulator
(SR) DC/DC power converters for embedded ap-
plications. The fi xed single output converters offer
both tight regulation and high effi ciency directly
at the power usage site and are a direct plug-in
replacement for TO-220 package 78xx series linear
regulators. Typically, no extra outside components
are required.
Two nominal output voltages are offered (3.3
and 5 VDC), each with 1.5 Amp maximum output.
Based on fi xed-frequency buck switching topology,
the high effi ciency means very low heat and little
electrical noise, requiring no external components.
The ultra wide input range is 7 to 36 Volts DC.
Protection features include short circuit current
limit protection. The OKI-78SR is designed to meet
all standards approvals. RoHS-6 (no lead) hazard-
ous material compliance is specifi ed as standard.
PRODUCT OVERVIEW
Connection Diagram
Figure 1. OKI-78SR
Note: Murata Power Solutions strongly recommends an external input fuse, F1.
See specifi cations.
External
DC
Power
Source
F1
CommonCommon
+Vin +Vout
Controller
Reference and
Error Amplifier
t4XJUDIJOH
t'JMUFST
t$VSSFOU4FOTF
FEATURES
Ultra wide 7 to 36 VDC input range
Fixed Outputs of 3.3 or 5 VDC up to 1.5 Amps
Vertical or horizontal SIP-mount, small footprint
package
“No heat sink” direct replacement for 3-terminal
78xx-series linear regulators
High effi ciency with no external components
Short circuit protection
Outstanding thermal derating performance
UL/EN/IEC 60950-1, 2nd Edition safety approvals
Typical units
MDC_OKI-78SR-W36.C03 Page 1 of 12
OKI-78SR Series
Fixed Output 1.5 Amp SIP DC/DC Converters
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