MSD1278T Datasheet, PDF (1/3 Pages) Coilcraft lnc. – Coupled Inductors

Document 704-1
Coupled Inductors –MSD1278T Forhightemperature
SEPIC applications
The MSD1278T series of coupled inductors was de-
signed for high temperature applications – up to 125°C.
The excellent coupling coefficient (k ≥ 0.94) makes it
ideal for use in SEPIC applications. In SEPIC topolo-
gies, the required inductance for each winding in a
coupled inductor is half the value needed for two sepa-
rate inductors, allowing selection of a part with lower
DCR and higher current handling.
These inductors provide high inductance, high effi-
ciency and excellent current handling in a rugged, low
cost part. They are well suited for use as VRM induc-
tors in high-current DC-DC and VRM/VRD controllers.
They can also be used as two single inductors con-
nected in series or parallel, as a common mode choke
or as a 1 : 1 transformer.
0.484
12,3
max
01.428,34max
123
X
Dot indicates pin1
Dash number
Internal code
0.308 ±0.010
7,8 ±0,25
0.197
5,0
0.197
5,0
34
21
0.138
3,5
0.059
1,5
Dimensions are in
inches
mm
Recommended
Land Pattern
0.157
4,0
0.217
5,5
2 1 _0.177
3 4 ^4,5
0.079
2,0
1
2
L1
L2
3
4
D1
+
+
L1
C1
V_IN
Q1
L2
+
C2
Load ^VOUT
–
–
Typical SEPIC schematic
Refer to Application Note, Document 639,
“Selecting Coupled Inductors for SEPIC Applications”
Core material Ferrite
Terminations RoHS compliant matte tin over nickel over phos
bronze. Other terminations available at additional cost.
Weight: 3.7 – 4.4 g
Ambient temperature –40°C to +125°C with Irms current, +125°C
to +165°C with derated current
Storage temperature Component: –40°C to +165°C.
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 Only pure water or alcohol recommended
Specifications subject to change without notice.
Please check our website for latest information.
Document 704-1 Revised 08/31/09
© Coilcraft, Inc. 2010