MSD1278T Datasheet, PDF (2/3 Pages) Coilcraft lnc. – Coupled Inductors

Document 704-2
High Temperature Coupled Inductors for SEPIC – MSD1278T
Part number¹
MSD1278T-472ML_
MSD1278T-562ML_
MSD1278T-682ML_
MSD1278T-822ML_
MSD1278T-103ML_
MSD1278T-123ML_
MSD1278T-153ML_
MSD1278T-183ML_
MSD1278T-223ML_
MSD1278T-273ML_
MSD1278T-333ML_
MSD1278T-393ML_
MSD1278T-473ML_
MSD1278T-563ML_
MSD1278T-683ML_
MSD1278T-823ML_
MSD1278T-104ML_
MSD1278T-124KL_
MSD1278T-154KL_
MSD1278T-184KL_
MSD1278T-224KL_
MSD1278T-274KL_
MSD1278T-334KL_
MSD1278T-394KL_
MSD1278T-474KL_
MSD1278T-564KL_
MSD1278T-684KL_
MSD1278T-824KL_
MSD1278T-105KL_
Inductance²
(µH)
4.7 ±20%
5.6 ±20%
6.8 ±20%
8.2 ±20%
10 ±20%
12 ±20%
15 ±20%
18 ±20%
22 ±20%
27 ±20%
33 ±20%
39 ±20%
47 ±20%
56 ±20%
68 ±20%
82 ±20%
100 ±20%
120 ±10%
150 ±10%
180 ±10%
220 ±10%
270 ±10%
330 ±10%
390 ±10%
470 ±10%
560
680
820
1000
±10%
±10%
±10%
±10%
DCR max³
(Ohms)
0.040
0.046
0.048
0.055
0.058
0.062
0.072
0.080
0.096
0.120
0.150
0.161
0.180
0.190
0.210
0.280
0.300
0.410
0.460
0.510
0.690
0.900
1.02
1.12
1.53
1.69
2.29
2.55
2.87
SRF typ⁴
(MHz)
33.0
30.0
23.0
20.0
17.0
15.0
13.0
12.0
11.0
10.0
9.5
8.5
7.5
7.0
6.5
5.0
4.5
4.3
4.1
4.0
3.4
3.1
2.9
2.7
2.2
2.0
1.7
1.4
1.3
10% drop
13.90
13.38
12.10
10.30
8.80
8.20
7.40
6.50
6.00
5.80
5.50
4.70
3.70
3.60
3.50
3.30
2.80
2.60
2.20
2.10
1.90
1.70
1.50
1.40
1.30
1.20
1.00
0.900
0.850
Isat (A)⁵
20% drop
15.20
14.86
13.56
11.52
10.00
9.18
8.36
7.38
6.80
6.56
6.10
5.26
4.34
4.18
4.04
3.72
3.24
2.94
2.54
2.42
2.16
1.94
1.70
1.60
1.50
1.34
1.08
1.04
0.948
30% drop
16.36
15.74
14.20
12.20
10.66
9.74
9.03
7.86
7.26
7.02
6.52
5.60
4.60
4.50
4.32
4.02
3.46
3.16
2.70
2.58
2.28
2.10
1.84
1.70
1.60
1.46
1.22
1.18
1.05
Irms (A)
both
one
windings⁶ winding⁷
3.16
4.47
2.87
4.06
2.81
3.98
2.76
3.90
2.56
3.62
2.48
3.50
2.30
3.25
2.18
3.08
1.99
2.81
1.78
2.52
1.59
2.25
1.54
2.18
1.45
2.05
1.41
2.00
1.35
1.90
1.16
1.65
1.13
1.59
0.96
1.36
0.91
1.29
0.86
1.22
0.74
1.05
0.65
0.92
0.61
0.86
0.58
0.82
0.50
0.70
0.47
0.67
0.41
0.58
0.39
0.55
0.37
0.52
1. When ordering, please specify termination and packaging code:
MSD1278T-105KLD
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
Winding power loss = (I_L12 + I_L22) × DCR in Watts (W)
Temperature rise (Δt) = Winding power loss × ^52.6°C
W
Δt
=
(I_L12
+
I_L22)
×
DCR
×
52.6°C
W
Example 1. MSD1278T-153ML (Equal current in each winding)
Winding power loss = (2.3 ² + 2.3 ²) × 0.072 = 0.761 W
Δt
=
0.761
W
×
52.6°C
W
= 40°C
Example 2. MSD1278T-153ML (I_L1 = 2.4 A, I_L2 = 1.3 A)
Winding power loss = (2.4 ² + 1.3 ²) × 0.072 = 0.536 W
Δt
=
0.536
W
×
52.6°C
W
=
28.2°C
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.
Specifications subject to change without notice.
Please check our website for latest information.
Document 704-2 Revised 08/31/09
© Coilcraft, Inc. 2010