Multifuse® Product Selection Worksheet

Bourns® Multifuse® Product Selection Worksheet
Selecting the appropriate Multifuse® Polymer PTC Resettable Fuse for your application is easy just follow these five steps:
STEP 1
What is the preferred product form factor?
❏ Radial Through-Hole – refer to the following data sheets:
__ MF-R Series
__ MF-RX/72 Series
__ MF-RHT Series for high temperature applications
__ MF-RG Series for automotive applications
❏ Surface Mount – refer to the following data sheets:
__ MF-SM Series
__ MF-MSMF Series
__ MF-USMF Series
__ MF-NSMF Series
__ MF-RX/250 Series for telecom applications
__ MF-R/600 Series for telecom applications
__ MF-R/90 Series for telecom applications
__ MF-SMDF Series
__ MF-SMHT Series for automotive applications
__ MF-SM/250 Series for telecom applications
❏ Strap (typically for battery packs) – refer to the following data sheets:
__ MF-S Series
__ MF-VS Series
__ MF-LS Series
__ MF-LR Series
__ MF-SVS Series
STEP 2
What is the normal operating current of the circuit?
(This is the equivalent of the Ihold specification of the Multifuse® Polymer PTC device.)
Hint: Select a Multifuse® Polymer PTC device with an Ihold greater than the operating current.
For example, if a customer wants a surface mount PTC device (e.g. one of the MF-MSMF models) and has an operating current of
900 mA, the MF-MSMF110 would be a suitable model as the Ihold of 1.1 A is greater than 900 mA.
Ihold
Model
MF-MSMF010
MF-MSMF014
MF-MSMF020
MF-MSMF030
MF-MSMF050
MF-MSMF075
MF-MSMF075/24
MF-MSMF110
MF-MSMF110/16
MF-MSMF125
MF-MSMF150
MF-MSMF160
MF-MSMF200
MF-MSMF250/16
MF-MSMF260
V max.
Volts
I max.
Amps
60.0
60.0
30.0
30.0
15.0
13.2
24.0
6.0
16.0
6.0
6.0
8.0
8.0
16.0
6.0
40
40
80
10
100
100
40
100
100
100
100
100
100
100
100
Itrip
Amperes
at 23 °C
Hold
Trip
0.10
0.14
0.20
0.30
0.50
0.75
0.75
1.10
1.10
1.25
1.50
1.60
2.00
2.50
2.60
0.30
0.34
0.40
0.60
1.00
1.50
1.50
2.20
2.20
2.50
3.00
2.80
4.00
5.00
5.20
Resistance
Ohms
at 23 °C
RMin.
R1Max.
0.70
15.00
0.40
6.50
0.40
6.00
Ihold of 1.1 A is greater
0.30
3.00than
operating current1.00
of 900 mA
0.15
0.11
0.45
0.11
0.45
0.04
0.21
0.04
0.21
0.035
0.14
0.03
0.120
0.035
0.099
0.020
0.065
0.015
0.100
0.015
0.080
Max. Time
To Trip
Amperes
at 23 °C
0.5
1.5
6.0
8.0
8.0
8.0
8.0
8.0
8.0
8.0
8.0
8.0
8.0
8.0
8.0
Seconds
at 23 °C
1.50
0.15
0.06
0.10
0.15
0.20
0.20
0.30
0.30
0.40
0.5
2.0
3.0
5.0
5.0
Tripped
Power
Dissipation
Watts
at 23 °C
Typ.
0.8
0.8
0.8
0.8
0.8
0.8
0.8
0.8
0.8
0.8
0.8
0.8
0.8
0.8
0.8
Bourns® Multifuse® Product Selection Worksheet
STEP 3
What is the maximum circuit voltage?
Hint: Select a Multifuse® Polymer PTC device with a Vmax greater than the circuit voltage.
For example, if a customer wants a surface mount PTC (e.g. one the MF-MSMF models) and has a maximum circuit voltage of
5 V, the MF-MSMF110 would be a suitable model as the Vmax of 6 V is greater than 5 V.
Ihold
Model
MF-MSMF010
MF-MSMF014
MF-MSMF020
MF-MSMF030
MF-MSMF050
MF-MSMF075
MF-MSMF075/24
MF-MSMF110
MF-MSMF110/16
MF-MSMF125
MF-MSMF150
MF-MSMF160
MF-MSMF200
MF-MSMF250/16
MF-MSMF260
V max.
Volts
I max.
Amps
60.0
60.0
30.0
30.0
15.0
13.2
24.0
6.0
16.0
6.0
6.0
8.0
8.0
16.0
6.0
40
40
80
10
100
100
40
100
100
100
100
100
100
100
100
Itrip
Resistance
Amperes
at 23 °C
Hold
Trip
Ohms
at 23 °C
RMin.
R1Max.
0.10
0.30
0.14
0.34
0.20
0.40
Vmax0.30
of 6 V is greater than
0.60
circuit
voltage of 5 V1.00
0.50
0.75
1.50
0.75
1.50
1.10
2.20
1.10
2.20
1.25
2.50
1.50
3.00
1.60
2.80
2.00
4.00
2.50
5.00
2.60
5.20
0.70
0.40
0.40
0.30
0.15
0.11
0.11
0.04
0.04
0.035
0.03
0.035
0.020
0.015
0.015
15.00
6.50
6.00
3.00
1.00
0.45
0.45
0.21
0.21
0.14
0.120
0.099
0.065
0.100
0.080
Max. Time
To Trip
Amperes
at 23 °C
0.5
1.5
6.0
8.0
8.0
8.0
8.0
8.0
8.0
8.0
8.0
8.0
8.0
8.0
8.0
Seconds
at 23 °C
1.50
0.15
0.06
0.10
0.15
0.20
0.20
0.30
0.30
0.40
0.5
2.0
3.0
5.0
5.0
Tripped
Power
Dissipation
Watts
at 23 °C
Typ.
0.8
0.8
0.8
0.8
0.8
0.8
0.8
0.8
0.8
0.8
0.8
0.8
0.8
0.8
0.8
STEP 4
What is the ambient temperature of the circuit?
Hint: Refer to the thermal derating chart of the data sheet and select a Multifuse® Polymer PTC device with an Ihold greater than
the operating current at that ambient temperature.
For example, if a customer wants a surface mount PTC device (e.g. one the MF-MSMF models) and has an operating current of
900 mA with a circuit ambient temperature of 40 °C, then the MF-MSMF110 would still be a suitable model as the Ihold of
950 mA at 40 °C is greater than the operating current of 900 mA.
Ambient Operating Temperature
Model
MF-MSMF010
MF-MSMF014
MF-MSMF020
MF-MSMF030
MF-MSMF050
MF-MSMF075
MF-MSMF075/24
MF-MSMF110
MF-MSMF110/16
MF-MSMF125
MF-MSMF150
MF-MSMF160
MF-MSMF200
MF-MSMF250/16
MF-MSMF260
-40 °C
0.16 / 0.32
0.23 / 0.52
0.29 / 0.58
0.44 / 0.88
0.77 / 1.54
1.15 / 2.30
1.15 / 2.30
1.59 / 3.18
1.59 / 3.18
1.80 / 3.61
2.17 / 4.34
2.30 / 5.00
3.08 / 5.40
3.9 / 7.8
4.00 / 7.98
-20 °C
0.14 / 0.28
0.19 / 0.45
0.26 / 0.52
0.39 / 0.78
0.68 / 1.36
1.01 / 2.02
1.01 / 2.02
1.43 / 2.86
1.43 / 2.86
1.63 / 3.25
1.95 / 3.90
2.20 / 4.40
2.71 / 4.74
3.42 / 6.84
3.52 / 7.01
0 °C
0.12 / 0.24
0.17 / 0.40
0.23 / 0.46
0.35 / 0.70
0.59 / 1.18
0.88 / 1.76
0.88 / 1.76
1.26 / 2.52
1.26 / 2.52
1.43 / 2.86
1.72 / 3.44
1.90 / 3.80
2.35 / 4.11
2.96 / 5.92
3.06 / 6.09
23 °C
0.11 / 0.22
0.14 / 0.34
0.20 / 0.40
0.30 / 0.60
0.50 / 1.00
0.75 / 1.50
0.75 / 1.50
1.10 / 2.20
1.10 / 2.20
1.25 / 2.50
1.50 / 3.00
1.60 / 2.80
2.00 / 3.50
2.50 / 5.00
2.60 / 5.15
40 °C
0.08 / 0.16
0.12 / 0.29
0.17 / 0.34
0.26 / 0.52
0.44 / 0.88
0.65 / 1.30
0.65 / 1.30
0.95 / 1.90
0.95 / 1.90
1.08 / 2.16
1.30 / 2.59
1.45 / 2.90
1.80 / 3.15
2.24 / 4.48
2.34 / 4.64
50 °C
60 °C
70 °C
0.07 / 0.14 0.06 / 0.12 0.05 / 0.10
0.10 / 0.25 0.09 / 0.23 0.08 / 0.21
0.15 / 0.30 0.14 / 0.28 0.12 / 0.24
0.23 / 0.46 I 0.21
/ 0.42
0.18than
/ 0.36
mA is greater
hold of 950
0.40 / 0.80 operating
0.37 / current
0.74 of 0.33
900 mA/ 0.66
0.60 / 1.20 0.55 / 1.10 0.49 / 0.98
0.60 / 1.20 0.55 / 1.10 0.49 / 0.98
0.87 / 1.74 0.80 / 1.60 0.71 / 1.42
0.87 / 1.74 0.80 / 1.60 0.71 / 1.42
0.99 / 1.98 0.91 / 1.82 0.81 / 1.62
1.18 / 2.37 1.09 / 2.18 0.97 / 1.94
1.30 / 2.60 1.15 / 2.30 1.03 / 2.06
1.60 / 2.80 1.50 / 2.63 1.40 / 2.40
1.98 / 3.96 1.85 / 3.70 1.29 / 2.58
2.08 / 4.13 1.95 / 3.87 1.39 / 2.74
85 °C
0.03 / 0.06
0.06 / 0.16
0.10 / 0.20
0.15 / 0.30
0.29 / 0.58
0.43 / 0.86
0.43 / 0.86
0.60 / 1.20
0.60 / 1.20
0.68 / 1.36
0.82 / 1.64
0.91 / 1.82
1.25 / 2.10
0.94 / 1.88
1.04 / 2.05
Bourns® Multifuse® Product Selection Worksheet
STEP 5
Request samples from your nearest Bourns representative and start testing in your application.
Circuit Protection Division
Asia-Pacific:
Tel: +886-2 2562-4117
Fax: +886-2 2562-4116
Europe:
Tel: +41-41 768 5555
Fax: +41-41 768 5510
The Americas:
Tel: +1-951 781-5500
Fax: +1-951 781-5700
www.bourns.com
COPYRIGHT© 2005, BOURNS, INC. LITHO IN U.S.A. 09/05 e/MF0525