The MSC1278 coupled inductors are designed with
high leakage inductance for use in SEPIC applications.
The loosely coupled windings (K ≈ 0.8) improve SEPIC
efficiency by reducing circulating current and provide
twice the ripple current reduction of separate inductors.
These inductors offer high efficiency and excellent cur-
rent handling in a rugged, low cost part. They are well
suited for use as a VRM inductors in high-current DC-DC
converters and VRM/VRD controllers.
They can also be used as two single inductors connected
in series or parallel.
Dot indicates pin1
2 1 0.177
3 4 4,5
Typical SEPIC schematic
Refer to Application Note, Document 639,
“Selecting Coupled Inductors for SEPIC Applications.”
for the Coilcraft on-line SEPIC Inductor Selector tool.
Core material Ferrite
Core and winding loss Go to online calculator
Terminations RoHS compliant matte tin over nickel over phos
bronze. Other terminations available at additional cost.
Ambient temperature –40°C to +85°C with Irms current, +85°C to
+125°C with derated current
Storage temperature Component: –40°C to +125°C.
Tape and reel packaging: –40°C to +80°C
Winding to winding isolation 500 Vrms
Resistance to soldering heat Max three 40 second reflows at
+260°C, parts cooled to room temperature between cycles
Moisture Sensitivity Level (MSL) 1 (unlimited floor life at <30°C /
85% relative humidity)
Failures in Time (FIT) / Mean Time Between Failures (MTBF)
38 per billion hours / 26,315,789 hours, calculated per Telcordia SR-332
Packaging 500/13″ reel; Plastic tape: 24 mm wide, 0.4 mm thick,
16 mm pocket spacing, 8.1 mm pocket depth
PCB washing Tested with pure water or alcohol only. For other
solvents, see Doc787_PCB_Washing.pdf.
US +1-847-639-6400 firstname.lastname@example.org
UK +44-1236-730595 email@example.com
Taiwan +886-2-2264 3646 firstname.lastname@example.org
China +86-21-6218 8074 email@example.com
Singapore + 65-6484 8412 firstname.lastname@example.org
Document 922-1 Revised 06/24/11
© Coilcraft Inc. 2013
This product may not be used in medical or high
risk applications without prior Coilcraft approval.
Specification subject to change without notice.
Please check web site for latest information.