Datasheet - Littelfuse

Radial Lead Fuses
MICRO™ > Very Fast-Acting Fuse > 272/273/274/278/279 Series
QPL
272/273/274/278/279 Series, MICRO™ Very Fast-Acting Fuse
Description
Developed originally for the U.S. Space Program,
MICRO™ fuse provides reliability in a compact design.
The MICRO™ fuse is available in plug–in or radial lead
styles and a complete range of ampere ratings from
0.002A to 5A to suit a wide variety of design needs.
Features
• Military grade available
• High breaking capacity
• Clear cover option to view • Plug-in with short or long
leads option
fuse element status
Agency Approvals
Agency
QPL
• Available from very low
ampere of 0.002A to 5A
Agency File Number
Ampere Range
E10480
0.002A - 5A
29862
0.002A - 5A
FM02
0.002A - 5A
Applications
• Printed circuit boards
and similar equipment
• Electronic components
Electrical Characteristics
% of Ampere
Rating
Ampere Rating
Opening Time
100%
0.002 – 5
4 Hours, Min.
0.002 – 0.3
5 Seconds, Max.
0.4 - 5
2 Seconds, Max.
200%
Electrical Characteristics
Ampere
Rating
(A)
.002
.005
.010
.015
.031
.050
.062
.100
.125
.200
.250
.300
.400
.500
.600
.700
.750
.800
1.00
01.5
2.00
3.00
*4.00
*5.00
Amp Code
(for all
above
series)
.002
.005
.010
.015
.031
.050
.062
.100
.125
.200
.250
.300
.400
.500
.600
.700
.750
.800
001.
01.5
002.
003.
004.
005.
Max
Voltage
Rating
(V)
125
125
125
125
125
125
125
125
125
125
125
125
125
125
125
125
125
125
125
125
125
125
125
125
Interrupting
Rating
10,[email protected]/VDC
Nominal
Cold
Resistance
(Ohms)
2200
280
80.0
44.0
16.0
3.52
2.55
1.38
1.0
2.30
1.75
1.25
0.227
0.167
0.430
0.324
0.293
0.271
0.0880
0.0578
0.0425
0.0275
0.0202
0.0156
Agency Approvals
Nominal
Melting
I2t (A2 sec)
0.00000000845
0.0000000766
0.000000462
0.00000123
0.00000810
0.0000666
0.000115
0.000385
0.000691
0.00409
0.00640
0.00945
0.0251
0.0716
0.0411
0.0710
0.0563
0.113
0.0648
0.160
0.300
0.759
1.38
2.21
QPL
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
* The fuses of 4A and 5A for 272 and 278 Series are obsolete.
© 2015 Littelfuse, Inc.
Specifications
are subject
to strongly
change without
notice.
Specifications are subject to change without notice.
Application
testing is
recommended.
Revised: 07/29/15
Radial Lead Fuses
MICRO™ > Very Fast-Acting Fuse > 272/273/274/278/279 Series
1/2 A
3/4 A
1A
1 1/2 A
2A
3A
4A
5A
1/4 A
1/8 A
1/16 A
1/32 A
100
1/100 A
1/64 A
Average Time Current Curves
1/200 A
Temperature Re-rating Curve
TIME IN SECONDS
10
1
0.1
Note:
1. Rerating depicted in this curve is in addition to the standard derating of 25% for
0.01
continuous operation.
0.001
0.005
0.01
0.1
1
CURRENT IN AMPERES
10
100
Soldering Parameters - Wave Soldering
Recommended Process Parameters:
280
260
Wave Parameter
240
220
Preheat:
200
(Depends on Flux Activation Temperature)
180
160
140
120
100
80
60
40
Lead-Free Recommendation
(Typical Industry Recommendation)
Temperature Minimum:
100° C
Temperature Maximum:
Preheat Time:
150° C
60-180 seconds
Solder Pot Temperature:
260° C Maximum
Solder Dwell Time:
2-5 seconds
Time (Seconds)
Cooling Time
Preheat Time
Dwell Time
240
230
220
210
200
190
180
170
160
150
140
130
120
110
90
100
80
70
60
50
40
30
0
0
20
20
10
Temperature (°C) - Measured on bottom side of board
300
Recommended Hand-Solder Parameters:
Solder Iron Temperature: 350° C +/- 5°C
Heating Time: 5 seconds max.
Note: These devices are not recommended for IR or
Convection Reflow process.
© 2015 Littelfuse, Inc.
Specifications are subject to change without notice.
Revised: 07/29/15
Radial Lead Fuses
MICRO™ > Very Fast-Acting Fuse > 272/273/274/278/279 Series
Dimensions
Product Characteristics
Operating Temperature:
273 and 279: –55ºC to +85ºC;
272 and 278: –55ºC to +125ºC
Fuses to MIL SPEC
Military QPL type (FM02).
To order, change 273 to 274.
Materials
272 and 278 series cap:
Nickel Plated Brass
273, 274 and 279 series cap:
Mirror polished Polycarbonate
Base: R-4 Ryton
Pins: Tin Plated Copper
Current and voltage ratings stamped
on cap
Product Marking
272 000 Series
(Short Lead, Metal Cap)
5.97
(.235")
7.30
(.29")
4.32
(.17")
2.54 (.10")
278 000 Series
(Long Lead, Metal Cap)
5.97
(.235")
7.30
(.29")
25.4 (1.0")
2.54 (.10")
Part Numbering System
273 000 and 274 000 Series
(Short Lead, Clear Plastic Cap)
0273 xxxx V
6.35
(.25")
8.89
(.35")
Series
4.32
(.17")
2.54 (.10")
Amp. Code
Refer to Amp Code column of
Electrical Characteristics Table
279 000 Series
Packaging Code
(Long Lead, Clear Plastic Cap)
6.35
(.25")
V=5
H = 100
8.89
(.35")
25.4 (1.0")
2.54 (.10")
Additional Information
NOTE: Amperage and voltage rating stamped on cap.
Leads are tin plated copper; .025" diameter.
Datasheet
272 Series
Datasheet
273 Series
Resources
272 Series
Resources
273 Series
Samples
272 Series
Samples
273 Series
Datasheet
274 Series
Resources
274 Series
Samples
274 Series
Datasheet
278 Series
Resources
278 Series
Samples
278 Series
Datasheet
279 Series
Resources
279 Series
Samples
279 Series
Packaging
Packaging
Option
Packaging
Specification
Quantity
Quantity &
Packaging
Code
Bulk
N/A
5
V
Bulk
N/A
100
H
© 2015 Littelfuse, Inc.
Specifications are subject to change without notice.
Revised: 07/29/15