Specifications subject to change without notice.
Please check our website for latest information.
US
UK
Taiwan
China
Singapore
+1-847-639-6400 sales@coilcraft.com
+44-1236-730595 sales@coilcraft-europe.com
+886-2-2264 3646 sales@coilcraft.com.tw
+86-21-6218 8074 sales@coilcraft.com.cn
+ 65-6484 8412 sales@coilcraft.com.sg
© 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.
Document 621-1
Document 621-1 Revised 01/13/12
Coupled Inductors
–
MSD7342
Dimensions are in inches
mm
Core material Ferrite
Terminations RoHS compliant matte tin over nickel over phos
bronze. Other terminations available at additional cost.
Weight 0.76 – 0.87g
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 200 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 250/7″ reel; 1000/13″ reel Plastic tape: 16 mm wide,
0.4 mm thick, 12 mm pocket spacing, 4.9 mm pocket depth
PCB washing Tested with pure water or alcohol only. For other solvents,
see Doc787_PCB_Washing.pdf.
For Flyback, SEPIC
and other Applications
• Tight coupling (k ≥ 0.97) and 200 V isolation make the MSD7342
series of coupled inductors ideal for use in a variety of circuits
including flyback, multi-output buck and SEPIC.
• They provide high inductance, high efficiency and excellent
current handling in a rugged, low cost part.
• Can also be used as two single inductors connected in series
or parallel, as a common mode choke or as a 1 : 1 transformer.
0.295
7,5 max
0.295
7,5 max
max
Dot indicates
pin 1
0.150
3,8
0.091
2,3
0.063
1,6
0.028
0,7
0.181
4,6
123
0.110
2,8
0.083
2,1
0.130
3,3
0.043
1,10
1
4
2
3
3
12
4
L1
L2
Recommended
Land Pattern
1
4
2
3
L1 L2
++
–
–
D
C
C
Typical Flyback Converter
VOUT
V
IN
SW
L1
L2
++
+
––
–
D
D
C
C
SW
Typical Buck Converter with auxiliary output
Typical SEPIC schematic
VOUT
VOUT
VOUTAUX
V
IN
V
IN
L1
L2
Q
C1
C
++
––
D
Coupled Inductors
–
MSD7342 Series
Specifications subject to change without notice.
Please check our website for latest information.
Document 621-2
Document 621-2 Revised 02/23/11
US
UK
Taiwan
China
Singapore
+1-847-639-6400 sales@coilcraft.com
+44-1236-730595 sales@coilcraft-europe.com
+886-2-2264 3646 sales@coilcraft.com.tw
+86-21-6218 8074 sales@coilcraft.com.cn
+ 65-6484 8412 sales@coilcraft.com.sg
© 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.
Document 621-2 Revised 01/13/12
Coupling Leakage Isat (A)6 Irms (A)
Inductance2 DCR max3
SRF typ4 coefficient
L typ5 10% 20% 30% both one
Part number1 ±20% (µH) (Ohms) (MHz) typ (µH) drop drop drop windings7
winding8
MSD7342-252ML_ 2.5 0.033 55 0.97 0.14 6.0 6.2 6.3 2.17 3.06
MSD7342-332ML_ 3.3 0.037 43 0.99 0.09 5.2 5.3 5.4 2.05 2.89
MSD7342-472ML_ 4.7 0.051 35 0.99 0.11 4.1 4.3 4.6 1.74 2.46
MSD7342-562ML_ 5.6 0.063 32 0.99 0.09 3.9 4.1 4.2 1.57 2.22
MSD7342-682ML_ 6.8 0.070 30 0.99 0.14 3.7 3.8 3.9 1.49 2.10
MSD7342-822ML_ 8.2 0.075 27 0.98 0.25 3.3 3.4 3.5 1.44 2.03
MSD7342-103ML_ 10 0.100 22 0.98 0.30 2.8 2.9 3.0 1.24 1.76
MSD7342-123ML_ 12 0.120 20 0.98 0.36 2.5 2.6 2.7 1.14 1.61
MSD7342-153ML_ 15 0.130 18 0.98 0.49 2.2 2.3 2.4 1.09 1.54
MSD7342-183ML_ 18 0.170 15 >0.99 0.16 2.0 2.2 2.3 0.95 1.35
MSD7342-223ML_ 22 0.220 13.5 >0.99 0.20 1.9 2.0 2.1 0.84 1.19
MSD7342-273ML_ 27 0.250 12.0 >0.99 0.20 1.7 1.8 1.9 0.79 1.11
MSD7342-333ML_ 33 0.270 11.0 >0.99 0.15 1.5 1.6 1.7 0.76 1.07
MSD7342-393ML_ 39 0.380 10.0 0.99 0.70 1.3 1.4 1.5 0.64 0.90
MSD7342-473ML_ 47 0.420 9.5 >0.99 0.30 1.2 1.3 1.4 0.61 0.86
MSD7342-563ML_ 56 0.460 8.7 >0.99 0.51 1.1 1.2 1.3 0.58 0.82
MSD7342-683ML_ 68 0.600 7.3 >0.99 0.51 1.0 1.1 1.2 0.51 0.72
MSD7342-823ML_ 82 0.680 6.2 0.99 1.17 0.90 1.00 1.1 0.48 0.67
MSD7342-104ML_ 100 0.770 5.5 >0.99 0.96 0.80 0.92 0.98 0.45 0.63
MSD7342-124ML_ 120 1.03 4.5 >0.99 0.61 0.70 0.80 0.90 0.39 0.55
MSD7342-154ML_ 150 1.35 4.0 >0.99 0.54 0.65 0.76 0.80 0.34 0.48
MSD7342-184ML_ 180 1.52 3.8 >0.99 0.75 0.62 0.66 0.73 0.32 0.45
MSD7342-224ML_ 220 1.72 3.5 >0.99 1.43 0.59 0.62 0.66 0.30 0.42
MSD7342-274ML_ 270 2.41 3.3 >0.99 1.56 0.55 0.57 0.60 0.25 0.36
MSD7342-334ML_ 330 2.70 3.0 >0.99 1.65 0.49 0.52 0.54 0.24 0.34
MSD7342-394ML_ 390 3.05 2.8 0.99 4.73 0.45 0.47 0.50 0.23 0.32
MSD7342-474ML_ 470 4.00 2.6 0.99 5.50 0.41 0.43 0.46 0.20 0.28
MSD7342-564ML_ 560 4.43 2.5 >0.99 4.85 0.38 0.40 0.42 0.19 0.26
MSD7342-684ML_ 680 5.00 2.3 0.99 7.59 0.36 0.37 0.38 0.18 0.25
MSD7342-824ML_ 820 6.80 2.2 >0.99 8.01 0.30 0.32 0.35 0.15 0.21
MSD7342-105ML_ 1000 7.80 2.0 >0.99 8.69 0.27 0.29 0.31 0.14 0.20
1. When ordering, please specify termination and packaging codes:
MSD7342-105MLC
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: C = 7″ machine-ready reel. EIA-481 embossed plastic
tape (250 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 C instead.
D = 13″ machine-ready reel. EIA-481 embossed plastic
tape. Factory order only, not stocked (1000 parts per
full reel).
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 the specified amount 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.
Temperature rise calculation based on specified Irms
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.
Temperature rise ( t) = Winding power loss × 129°C
W
∆
∆t =×
129°C
W
(+) × DCRII
L12L22
Winding power loss = (+) × DCR in Watts (W)II
L1
2
L2
2
Example 1. MSD7342-123ML (Equal current in each winding)
Winding power loss = (1.14 + 1.14 ) × 0.120 = 0.312 W
t = 0.312 W × 129°C
W= 40°C
22
∆
Example 2. (= 1.4 A,
Winding p
MSD7342-123ML = 0.6 A)II
L1 L2
22
ower loss = (1.4 + 0.6 ) × 0.120 = 0.278 W
t = 0.278 W × 129°C
W
= 36°C
∆
Coupled Inductors
–
MSD7342 Series
Specifications subject to change without notice.
Please check our website for latest information.
Document 621-3
Document 621-3 Revised 02/23/11
US
UK
Taiwan
China
Singapore
+1-847-639-6400 sales@coilcraft.com
+44-1236-730595 sales@coilcraft-europe.com
+886-2-2264 3646 sales@coilcraft.com.tw
+86-21-6218 8074 sales@coilcraft.com.cn
+ 65-6484 8412 sales@coilcraft.com.sg
© 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.
Document 621-3 Revised 01/13/12
Typical L vs Current Typical L vs Frequency
Irms Derating
1
10
100
1000
10000
0.01 0.1 101
Current (A)
Inductance (µH)
4.7 µH
10 µH
47 µH
100 µH
470 µH
1000 µH
1
10
100
1000
10000
0.1 1 10010
Frequency (MHz)
Inductance (µH)
4.7 µH
10 µH
47 µH
100 µH
470 µH
1000 µH
-40 -20 020406080100 140120
Ambient temperature (°C)
120
110
100
90
80
70
60
50
40
30
20
10
0
25°C
Percent of rated rmsI
