© Coilcraft, Inc. 2010
High Temperature Coupled Inductors for SEPIC – MSD1278T
Specifications subject to change without notice.
Please check our website for latest information.
Document 704-2
Revised 08/31/09
Document 704-2
Irms(A)
Inductance2
DCRmax3
SRF typ4
Isat (A)5
both
one
Part number1
(µH)
(Ohms)
(MHz)
10%drop
20%drop
30%drop
windings6
winding7
MSD1278T-472ML_
4.7 ±20%
0.040
33.0
13.90
15.20
16.36
3.16
4.47
MSD1278T-562ML_
5.6 ±20%
0.046
30.0
13.38
14.86
15.74
2.87
4.06
MSD1278T-682ML_
6.8 ±20%
0.048
23.0
12.10
13.56
14.20
2.81
3.98
MSD1278T-822ML_
8.2 ±20%
0.055
20.0
10.30
11.52
12.20
2.76
3.90
MSD1278T-103ML_
10
±20%
0.058
17.0
8.80
10.00
10.66
2.56
3.62
MSD1278T-123ML_
12
±20%
0.062
15.0
8.20
9.18
9.74
2.48
3.50
MSD1278T-153ML_
15
±20%
0.072
13.0
7.40
8.36
9.03
2.30
3.25
MSD1278T-183ML_
18
±20%
0.080
12.0
6.50
7.38
7.86
2.18
3.08
MSD1278T-223ML_
22
±20%
0.096
11.0
6.00
6.80
7.26
1.99
2.81
MSD1278T-273ML_
27
±20%
0.120
10.0
5.80
6.56
7.02
1.78
2.52
MSD1278T-333ML_
33
±20%
0.150
9.5
5.50
6.10
6.52
1.59
2.25
MSD1278T-393ML_
39
±20%
0.161
8.5
4.70
5.26
5.60
1.54
2.18
MSD1278T-473ML_
47
±20%
0.180
7.5
3.70
4.34
4.60
1.45
2.05
MSD1278T-563ML_
56
±20%
0.190
7.0
3.60
4.18
4.50
1.41
2.00
MSD1278T-683ML_
68
±20%
0.210
6.5
3.50
4.04
4.32
1.35
1.90
MSD1278T-823ML_
82
±20%
0.280
5.0
3.30
3.72
4.02
1.16
1.65
MSD1278T-104ML_
100
±20%
0.300
4.5
2.80
3.24
3.46
1.13
1.59
MSD1278T-124KL_
120
±10%
0.410
4.3
2.60
2.94
3.16
0.96
1.36
MSD1278T-154KL_
150
±10%
0.460
4.1
2.20
2.54
2.70
0.91
1.29
MSD1278T-184KL_
180
±10%
0.510
4.0
2.10
2.42
2.58
0.86
1.22
MSD1278T-224KL_
220
±10%
0.690
3.4
1.90
2.16
2.28
0.74
1.05
MSD1278T-274KL_
270
±10%
0.900
3.1
1.70
1.94
2.10
0.65
0.92
MSD1278T-334KL_
330
±10%
1.02
2.9
1.50
1.70
1.84
0.61
0.86
MSD1278T-394KL_
390
±10%
1.12
2.7
1.40
1.60
1.70
0.58
0.82
MSD1278T-474KL_
470
±10%
1.53
2.2
1.30
1.50
1.60
0.50
0.70
MSD1278T-564KL_
560
±10%
1.69
2.0
1.20
1.34
1.46
0.47
0.67
MSD1278T-684KL_
680
±10%
2.29
1.7
1.00
1.08
1.22
0.41
0.58
MSD1278T-824KL_
820
±10%
2.55
1.4
0.900
1.04
1.18
0.39
0.55
MSD1278T-105KL_
1000
±10%
2.87
1.3
0.850
0.948
1.05
0.37
0.52
1. When ordering, please specify termination and packaging code:
MSD1278T-105K
LD
Termination: L = RoHS compliant matte tin over nickel over phos bronze
Special order: T = RoHS tin-silver-copper (95.5/4/0.5) or
S = non-RoHS tin-lead (63/37).
Packaging:
D =13
″ machine-ready reel. EIA-481 embossed plastic
tape (500 parts per full reel).
B = Less than full reel. In tape, but not machine ready.
To have a leader and trailer added ($25 charge), use
code letter D instead.
2. Inductance shown for each winding, measured at 100 kHz, 0.1 Vrms, 0
Adc on an Agilent/HP 4284A LCR meter or equivalent. When leads are
connected in parallel, inductance is the same value. When leads are
connected in series, inductance is four times the value.
3. DCR is for each winding. When leads are connected in parallel, DCR is
half the value. When leads are connected in series, DCR is twice the
value.
4. SRF measured using an Agilent/HP 4191A or equivalent. When leads
are connected in parallel, SRF is the same value.
5. DC current, at which the inductance drops the specified amount from its
value without current. It is the sum of the current flowing in both
windings.
6. Equal current when applied to each winding simultaneously that causes
a 40°C temperature rise from 25°C ambient. See temperature rise
calculation.
7. Maximum current when applied to one winding that causes a 40°C
temperature rise from 25°C ambient. See temperature rise calculation.
8. Electrical specifications at 25°C.
Refer to Doc 639 “Selecting Coupled Inductors for SEPIC Applications.”
Refer to Doc 362 “Soldering Surface Mount Components” before soldering.
Temperature rise calculation based on specified Irms
Temperature rise ( t) = Winding power loss ×
52.6°C
W
Δ
Δt =
×
52.6°C
W
(
+
) × DCR
II
L1
2
L2
2
Winding power loss = (
+
) × DCR in Watts (W)
II
L1
2
L2
2
Example 1. MSD1278T-153ML (Equal current in each winding)
Winding power loss = (2.3 + 2.3 ) × 0.072 = 0.761 W
t = 0.761 W ×
52.6°C
W
= 40°C
22
Δ
Example 2.
(
= 2.4 A,
Winding p
MSD1278T-153ML
= 1.3 A)
II
L1
L2
22
ower loss = (2.4 + 1.3 ) × 0.072 = 0.536 W
t = 0.536 W ×
52.6°C
W
= 28.2°C
Δ
Coupled Inductor Core and Winding Loss Calculator
This web-based utility allows you to enter frequency, peak-to-peak (ripple)
current, and
Irms current to predict temperature rise and overall losses,
including core loss. Visit www.coilcraft.com/coupledloss.