MSD1278

Document 499-1
Coupled Inductors MSD1278
For Flyback, SEPIC, Zeta
and other Applications
• Tight coupling (k ≥ 0.98) and 500 V isolation
• High inductance and high efficiency
• Excellent current handling
• Ideal for use in a variety of circuits including flyback, multi-output
buck, SEPIC and Zeta.
• Can also be used as two single inductors connected in series
or parallel or as a common mode choke.
+
+
D
L1
C
L2
VOUT
C
VIN
–
SW
–
Typical Flyback Converter
D
L2
+
VOUT
C
AUX
–
+
0.484
max
12,3
0.484
max
12,3
123
X
+
VIN
Dot indicates pin1
L1
D
SW
–
–
Typical Buck Converter with auxiliary output
Dash number
Internal code
D
+
L1
VIN
0.317
max*
8,05
Recommended
Land Pattern
0.197
5,0
3
2
3
0.059
1,5
* For optional tin-lead and tin-silver-copper
terminations, dimensions are for the mounted
part. Dimensions before mounting can be
an additional 0.012 inch (0,3 mm).
L2
C
+
1
Q
0.177
4,5
4
VIN
–
0.079
2,0
1
VOUT
–
Typical SEPIC schematic
+
2
1
+
C1
Q
–
0.157
4,0
4
inches
Dimensions are in
mm
C
0.217
5,5
0.197
5,0
0.138
3,5
VOUT
C
C
L2
C1
L1
D
Typical Zeta schematic
C
VOUT
–
2
L1
L2
4
3
1:1
Document 499-1 Revised 04/05/13
Document 499-2
Coupled Inductors – MSD1278 Series
Inductance2
DCR max3 SRF typ4
Part
number1
(µH)
(Ohms)
(MHz)
Irms (A)
CouplingLeakage
one
windings7 winding8
typ
typ (µH)
(A)
coefficient inductance5 Isat6both
MSD1278-472ML_ 4.7 ±20%
MSD1278-562ML_ 5.6 ±20%
MSD1278-682ML_ 6.8 ±20%
MSD1278-822ML_ 8.2 ±20%
MSD1278-103ML_ 10 ±20%
0.038
0.046
0.048
0.050
0.058
32.0
25.0
24.0
18.0
16.5
0.98
0.98
0.98
0.98
0.98
0.22
0.23
0.22
0.34
0.34
14.9
13.4
13.1
10.8
10.5
3.16
2.87
2.81
2.76
2.56
4.47
4.06
3.98
3.90
3.62
MSD1278-123ML_ 12 ±20%
MSD1278-153ML_ 15 ±20%
MSD1278-183ML_ 18 ±20%
MSD1278-223ML_ 22 ±20%
MSD1278-273ML_ 27 ±20%
0.062
0.072
0.080
0.096
0.120
14.5
11.8
10.5
9.0
8.4
0.98
0.99
0.99
0.99
0.99
0.36
0.41
0.37
0.41
0.43
9.6
9.1
8.0
6.8
6.5
2.48
2.30
2.18
1.99
1.78
3.50
3.25
3.08
2.81
2.52
MSD1278-333ML_ 33 ±20%
MSD1278-393ML_ 39 ±20%
MSD1278-473ML_ 47 ±20%
MSD1278-563ML_ 56 ±20%
MSD1278-683ML_ 68 ±20%
0.150
0.160
0.180
0.190
0.210
7.6
6.5
6.0
5.6
5.0
0.99
0.99
0.99
0.99
0.99
0.56
0.64
0.70
0.76
0.88
5.6
5.5
5.2
4.5
4.1
1.59
1.54
1.45
1.41
1.35
2.25
2.18
2.05
2.00
1.90
MSD1278-823ML_ 82 ±20%
MSD1278-104ML_ 100 ±20%
MSD1278-124KL_ 120 ±10%
MSD1278-154KL_ 150 ±10%
MSD1278-184KL_ 180 ±10%
0.280
0.300
0.410
0.460
0.510
4.1
3.6
3.2
3.0
2.7
0.99
>0.99
0.99
>0.99
>0.99
0.85
0.90
1.31
1.46
0.93
3.8
3.4
3.2
2.8
2.5
1.16
1.13
0.96
0.91
0.86
1.65
1.59
1.36
1.29
1.22
MSD1278-224KL_ MSD1278-274KL_ MSD1278-334KL_ MSD1278-394KL_ MSD1278-474KL_ 0.690
0.900
1.02
1.12
1.43
2.5
2.1
2.0
1.8
1.6
>0.99
>0.99
0.99
>0.99
>0.99
1.54
1.17
4.14
1.64
0.25
2.3
2.1
1.9
1.7
1.6
0.74
0.65
0.61
0.58
0.50
1.05
0.92
0.86
0.82
0.70
1.69
2.29
2.55
2.83
1.5
1.4
1.3
1.1
>0.99
>0.99
>0.99
>0.99
2.68
2.11
2.39
4.28
1.5
1.3
1.2
1.1
0.47
0.41
0.39
0.37
0.67
0.58
0.55
0.52
220 ±10%
270 ±10%
330 ±10%
390 ±10%
470 ±10%
MSD1278-564KL_ 560 ±10%
MSD1278-684KL_ 680 ±10%
MSD1278-824KL_ 820 ±10%
MSD1278-105KL_
1000 ±10%
1. When ordering, please specify termination and packaging code:
Coupled Inductor Core and Winding Loss Calculator
MSD1278-105KLD
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. Leakage inductance is for L1 and is measured with L2 shorted.
6. DC current, at which the inductance drops 30% (typ) from its value
without current. It is the sum of the current flowing in both windings.
7. Equal current when applied to each winding simultaneously that causes
a 40°C temperature rise from 25°C ambient. See temperature rise calculation.
8. Maximum current when applied to one winding that causes a 40°C
temperature rise from 25°C ambient. See temperature rise calculation.
9. 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.
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. Go to online calculator.
Designer’s Kit C400 contains 3 each of all values.
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.
Weight: 3.7 – 4.4 g
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 and winding-to-core 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, 0.5 mm thick,
16 mm pocket spacing, 8.7 mm pocket depth
PCB washing Tested to MIL-STD-202 Method 215 plus an additional
aqueous wash. See Doc787_PCB_Washing.pdf.
Document 499-2 Revised 04/05/13
Document 499-3
Coupled Inductors – MSD1278 Series
Typical L vs Current
Typical L vs Frequency
10000
10000
-105
-474
-104
100
-473
-103
10
-105
1000
Inductance (µH)
Inductance (µH)
1000
-474
-104
100
-473
-103
10
-472
1
0.1
1
-472
10
100
Current (A)
1
0.01
0.1
1
10
Frequency (MHz)
Current Derating
100
90
80
70
60
50
40
30
20
10
0
25°C
Percent of rated current
120
110
Isat
Irms
-40
-20
0
20
40
60
80
100
120 140
Ambient temperature (°C)
Document 499-3 Revised 04/05/13