Accu-Guard Series LGA/SMD
Thin-Film Fuse

090823

IMPORTANT INFORMATION/DISCLAIMER
All product specifications, statements, information and data (collectively, the “Information”) in this datasheet
or made available on the website are subject to change. The customer is responsible for checking and verifying
the extent to which the Information contained in this publication is applicable to an order at the time the order isplaced. All Information given herein is believed to be accurate and reliable, but it is presented without guarantee,
warranty, or responsibility of any kind, expressed or implied.
Statements of suitability for certain applications are based on KYOCERA AVX’s knowledge of typical operating
conditions for such applications, but are not intended to constitute and KYOCERA AVX specifically disclaims
any warranty concerning suitability for a specific customer application or use.
ANY USE OF PRODUCT OUTSIDE OF SPECIFICATIONS OR ANY STORAGE OR INSTALLATIONINCONSISTENT WITH PRODUCT GUIDANCE VOIDS ANY WARRANTY.
The Information is intended for use only by customers who have the requisite experience and capability todetermine the correct products for their application. Any technical advice inferred from this Information orotherwise provided by KYOCERA AVX with reference to the use of KYOCERA AVX’s products is given without
regard, and KYOCERA AVX assumes no obligation or liability for the advice given or results obtained.
Although KYOCERA AVX designs and manufactures its products to the most stringent quality and safety
standards, given the current state of the art, isolated component failures may still occur. Accordingly, customer
applications which require a high degree of reliability or safety should employ suitable designs or othersafeguards (such as installation of protective circuitry or redundancies) in order to ensure that the failure of anelectrical component does not result in a risk of personal injury or property damage.
Unless specifically agreed to in writing, KYOCERA AVX has not tested or certified its products, services ordeliverables for use in high risk applications including medical life support, medical device, direct physicalpatient contact, water treatment, nuclear facilities, weapon systems, mass and air transportation control,
flammable environments, or any other potentially life critical uses. Customer understands and agrees that
KYOCERA AVX makes no assurances that the products, services or deliverables are suitable for any highrisk uses. Under no circumstances does KYOCERA AVX warrant or guarantee suitability for any customer
design or manufacturing process.

Although all product–related warnings, cautions and notes must be observed, the customer should not assume
that all safety measures are indicted or that other measures may not be required.

The Important Information/Disclaimer is incorporated in the catalog where these specifications came from or available
online at www.kyocera-avx.com/disclaimer/ by reference and should be reviewed in full before placing any order.
121119– accu-guard series lga/smd thin-film fuse –Accu-Guard Series
LGA/SMD Thin-Film Fuse
Table of Contents
Accu-Guard®
Introduction............................................................................................................................................... 1• ACCU–GUARD® TECHNOLOGY.................................................................................................................................................1• FEATURES...................................................................................................................................................................................1• DIMENSIONS..............................................................................................................................................................................1• HOW TO ORDER.........................................................................................................................................................................1• APPLICATIONS...........................................................................................................................................................................1• APPROVAL FILE NUMBERS.......................................................................................................................................................1

Accu-Guard® II Low Current
LGA Miniature 0402 and 0603 Size Thin-Film Fuses.................................................................................... 2• ELECTRICAL SPECIFICATIONS.................................................................................................................................................2• ENVIRONMENTAL CHARACTERISTICS....................................................................................................................................2• RECOMMENDED PAD LAYOUT..................................................................................................................................................2• FUSE TIME–CURRENT CHARACTERISTICS.............................................................................................................................3• FUSE PRE–ARC JOULE INTEGRALS VS CURRENT..................................................................................................................4• FUSE PRE–ARC JOULE INTEGRALS VS PRE–ARC TIME........................................................................................................5

Accu-Guard® II
SMD Thin-Film Fuse................................................................................................................................... 6• ELECTRICAL SPECIFICATIONS.................................................................................................................................................6• ENVIRONMENTAL CHARACTERISTICS....................................................................................................................................7

Lead-Free SMD Thin-Film Fuse................................................................................................................... 8• FUSE TIME – CURRENT CHARACTERISTICS FOR TYPE F0402E (TYPICAL).........................................................................8• FUSE PRE-ARC JOULE INTEGRALS VS CURRENT FOR TYPE F0402E (TYPICAL).................................................................9• FUSE PRE-ARC JOULE INTEGRALS VS PRE-ARC TIME FOR TYPE F0402E (TYPICAL).........................................................10• FUSE TIME – CURRENT CHARACTERISTICS FOR TYPE F0603E (TYPICAL).........................................................................11• FUSE PRE-ARC JOULE INTEGRALS VS CURRENT FOR TYPE F0603E (TYPICAL).................................................................12• FUSE PRE-ARC JOULE INTEGRALS VS PRE-ARC TIME FOR TYPE F0603E (TYPICAL).........................................................13• FUSE TIME - CURRENT CHARACTERISTICS FOR TYPES F0805B AND F1206B (TYPICAL).................................................14• FUSE PRE-ARC JOULE INTEGRALS VS. CURRENT TIME FOR TYPES F0805B AND F1206B (TYPICAL).............................15• FUSE PRE-ARC JOULE INTEGRALS VS. PRE-ARC TIME FOR TYPES F0805B AND F1206B (TYPICAL)...............................16• FUSE TIME - CURRENT CHARACTERISTICS FOR TYPE F0612D (TYPICAL)*........................................................................17• FUSE PRE-ARC JOULE INTEGRALS VS. PRE-ARC TIME FOR TYPE F0612D (TYPICAL)*......................................................18

Accu-Guard®
SMD Thin-Film Fuse Handling and Soldering............................................................................................. 20• QUALITY & RELIABILITY............................................................................................................................................................20• HANDLING AND SOLDERING....................................................................................................................................................20• CIRCUIT BROAD TYPE................................................................................................................................................................20• WAVE SOLDERING.....................................................................................................................................................................20• COMPONENT PAD DESIGN.......................................................................................................................................................20• PREHEAT & SOLDERING............................................................................................................................................................20• HAND SOLDERING & REWORK..................................................................................................................................................20• COOLING.....................................................................................................................................................................................20• REFLOW SOLDERING.................................................................................................................................................................20*Not recommended for new designs, please contact factory

The Important Information/Disclaimer is incorporated in the catalog where these specifications came from or available
online at www.kyocera-avx.com/disclaimer/ by reference and should be reviewed in full before placing any order.

– accu-guard series lga/smd thin-film fuse –Accu-Guard Series
LGA/SMD Thin-Film Fuse
Table of Contents• RECOMMENDED SOLDERING PROFILES.................................................................................................................................21• CLEANING RECOMMENDATIONS.............................................................................................................................................21• STORAGE CONDITIONS.............................................................................................................................................................21• PACKAGING................................................................................................................................................................................22• REEL DIMENSIONS....................................................................................................................................................................22• CARRIER DIMENSIONS..............................................................................................................................................................22

Fuse Selection Guide................................................................................................................................ 23• HOW TO CHOOSE THE CORRECT ACCU–GUARD FUSE FOR CIRCUIT PROTECTION...........................................................23• DESIGN PARAMETERS...............................................................................................................................................................23• DESIGNING FOR CURRENT PULSE SITUATIONS.....................................................................................................................24

The Important Information/Disclaimer is incorporated in the catalog where these specifications came from or available
online at www.kyocera-avx.com/disclaimer/ by reference and should be reviewed in full before placing any order.

– accu-guard series lga/smd thin-film fuse –Accu-Guard®
Introduction
ACCU–GUARD® TECHNOLOGYThe Accu-Guard® series of fuses is based on thin-film techniques. This
technology provides a level of control on the component electrical andphysical characteristics that is generally not possible with standard fusetechnologies. This has allowed KYOCERA AVX to offer a series of devices
which are designed for modern surface mount circuit boards which require
protection.

FEATURES

•
•
•
•
•
•

Accurate current rating
Fast acting
Small-standard 0402, 0805, 1206 and 0612 chip sizes
Taped and reeled
Completely compatible with all soldering systems used for SMT
Lead Free Series (F0201G, F0402G, F0603G, F0402E, F0603E, F0805B,
F1206B)

APPLICATIONS

•
•
•
•
•
•
•
•
•
•
•
•

Two-Way RadiosHome Appliances
Battery Management Systems
Battery Chargers
Rechargeable Battery Packs
Computers
Hard Disk Drives
PDA’s
LCD Screens
For RoHS compliant products, please
SCSI Interface
select correct termination style.
Digital Cameras
Video Cameras

APPROVAL FILE NUMBERS• UL, cUL: RCD#E143842

DIMENSIONS mm (inches)
F0402E and F0603E

F0805B and F1206B

F0201G, F0402G, F0603G

B1

B

S
A

B
H

W

T

T

T
L

W

B2

L

W

L

F0201G

F0402G

F0603G

F0402E

F0603E

F0805B

F1206BL

0.60 ± 0.05
(0.023 ± 0.002)

1.00±0.05(0.039±0.002)

1.60±0.10(0.063±0.004)

1.00±0.10(0.039±0.004)

1.60±0.10(0.063±0.004)

2.10±0.20(0.083±0.008)

3.10±0.20(0.122±0.008)

W

0.325 ± 0.05
(0.0128 ± 0.002)

0.58 ±0.04(0.023±0.002)

0.81±0.10(0.032±0.004)

0.55±0.07(0.022±0.003)

0.81±0.10(0.032±0.004)

1.27±0.10(0.050±0.004)

1.60±0.10(0.063±0.004)

T

0.225 ± 0.05
(0.009 ± 0.002)

0.35±0.05(0.014±0.002)

0.61±0.10(0.024±0.004)

0.40±0.10(0.016±0.004)

0.63±0.10(0.025±0.004)

0.90±0.2(0.035±0.008)

1.20±0.20(0.047±0.008)

B

0.10 ± 0.025(0.004 ± 0.001)

0.48±0.05(0.019±0.002)

0.71±0.05(0.028±0.002)

0.20±0.10(0.008±0.004)

0.35±0.15(0.014±0.006)

0.30±0.15(0.012±0.006)

0.43±0.25(0.017±0.010)

A

0.275 ± 0.025(0.011 ± 0.001)

0.20±0.05(0.008±0.002)

0.28±0.05(0.011±0.002)

S, H

0.025 ± 0.025(0.001 ± 0.001)

0.05±0.05(0.002±0.002)

0.05±0.05(0.002±0.002)

HOW TO ORDER
F
Product Fuse

0603

A

0R20

F

Size

Fuse Version

Rated Current

Fuse Speed

See table forstandard sizes

B= Accu-Guard® II
E= Accu-Guard® II 0402, 0603
G= Accu-Guard® II Low Current
0201, 0402, 0603

Current expressed inAmps. Letter R denotes decimal point
e.g. 0.20A=0R20
1.75A=1R75

F = Fast

W

TR

Termination

Packaging

TR = Tape and reelS = Nickel/Lead-Free
Solder coated(Sn 100), SMD
W = Nickel/solder coated(Sn 63, Pb 37)
Solder Coated (Sn100)
N = Nickel/Lead-Free
Solder Coated (Sn100), LGA

The Important Information/Disclaimer is incorporated in the catalog where these specifications came from or available
online at www.kyocera-avx.com/disclaimer/ by reference and should be reviewed in full before placing any order.
TDS-FUSE-0002 | Rev 5– accu-guard series lga/smd thin-film fuse –1

Accu-Guard® II Low Current
LGA Miniature 0201, 0402 and 0603 Size Thin-Film Fuses
RECOMMENDED PAD LAYOUT mm (inches)

The new Accu-Guard® series of fuses is based on thin-film
technology which allows precise control of the component
electrical and physical characteristics that is not possible withstandard fuse technologies. The Accu-Guard Low Current
series encompasses the lowest current ratings in compact
0402 and 0603 packages and features LGA terminations.

F0201G

ELECTRICAL SPECIFICATIONS

F0402G

Operating temperature: -55°C to +125°C
Current carrying capacity:-55°C to -11°C 107% of rating-10°C to +60°C 100% of rating+61°C to +100°C 85% of rating+101°C to +125°C 80% of rating
Rated voltage: 32V (0201), 63V (F0603G), 32V (F0402G)
Post-fusing resistance: >1MΩInterrupt rating: 50A
Termination: Nickel/Solder

F0603G
0.55(0.022)0.31 (0.012)
0.85 (0.033)

1.15 (0.045)

Current
RatingA

Part Number

Resistance@0.1 x I rated
Ω (max.)Voltage Drop
@ I rated
mV (max.)

2.4 (0.095)

Fusing Current(within 5 sec)A

Pre-Arc I2t@10x I rated A 2sec (typ)

Color
Code
Green

F0201G0R02FNTR / F0402G0R02FNTR / F0603G0R02FNTR

0.028

7.5

290

0.070

6 x 10 -7

F0201G0R03FNTR / F0402G0R03FNTR / F0603G0R03FNTR

0.0375

4.8

230

0.094

8 x 10 -7

Red

F0201G0R05FNTR / F0402G0R05FNTR / F0603G0R05FNTR

0.050

3.4

250

0.125

2 x 10 -6

Blue

F0201G0R06FNTR / F0402G0R06FNTR / F0603G0R06FNTR

0.062

2.5

280

0.155

2 x 10 -6

Yellow

F0201G0R07FNTR / F0402G0R07FNTR / F0603G0R07FNTR

0.075

2.0

280

0.188

4 x 10 -6

Brown

F0201G0R10FNTR / F0402G0R10FNTR / F0603G0R10FNTR

0.100

2.4

300

0.250

7 x 10 -6

Red

F0201G0R12FNTR / F0402G0R12FNTR / F0603G0R12FNTR

0.125

1.6

250

0.312

1 x 10 -5

White
Green

F0201G0R15FNTR / F0402G0R15FNTR / F0603G0R15FNTR

0.150

1.2

220

0.375

2 x 10 -5

F0201G0R20FNTR* / F0402G0R20FNTR / F0603G0R20FNTR

0.200

0.8

210

0.500

4 x 10 -5

Pink

F0402G0R25FNTR / F0603G0R25FNTR

0.25

0.55

180

0.625

2 x 10 -4

Blue

F0402G0R37FNTR / F0603G0R37FNTR

0.375

0.30

150

0.938

3 x 10 -4

Red

F0402G0R50FNTR / F0603G0R50FNTR

0.5

0.20

140

1.25

7 x 10 -4

Green*Blue Color Code

ENVIRONMENTAL CHARACTERISTICS
Test

Conditions

Required

Solderability

Components completely immersed in a solder bathat 245 ±5°C for 3 secs.

Total area of imperfections in solder
coatup to 5% of the land suface area

Leach
ResistanceComponents completely immersed in a solder bathat 255 ±5°C for 60 secs.

Dissolution of termination≤ 15% of the land surface area

Storage

12 months minimum with components stored in “asreceived” packaging.

Good solderability

Shear

Components mounted to a substrate. Increasing
shearing force applied paralled to the sufstrate till
destruction.

Destruction at 5N force minimum

Temperature
Cycling

Components mounted to a flexible substrate (e.g.
FR – 4). 1000 cycles -55ºC to +125ºC.

No Visible damage∆R/R<10%

Tested as shown in diagram

Bend

3 mm
Deflection

45mm

2

1.1
(0.043)45mm

No visible damage∆R/R<10%The Important Information/Disclaimer is incorporated in the catalog where these specifications came from or available
online at www.kyocera-avx.com/disclaimer/ by reference and should be reviewed in full before placing any order.
TDS-FUSE-0002 | Rev 5– accu-guard series lga/smd thin-film fuse –Accu-Guard® II Low Current
LGA Miniature 0201, 0402 and 0603 Size Thin-Film Fuses
FUSE TIME–CURRENT CHARACTERISTICS

The Important Information/Disclaimer is incorporated in the catalog where these specifications came from or available
online at www.kyocera-avx.com/disclaimer/ by reference and should be reviewed in full before placing any order.
TDS-FUSE-0002 | Rev 5– accu-guard series lga/smd thin-film fuse –3

Accu-Guard® II Low Current
LGA Miniature 0201, 0402 and 0603 Size Thin-Film Fuses
FUSE PRE–ARC JOULE INTEGRALS VS CURRENT

4The Important Information/Disclaimer is incorporated in the catalog where these specifications came from or available
online at www.kyocera-avx.com/disclaimer/ by reference and should be reviewed in full before placing any order.
TDS-FUSE-0002 | Rev 5– accu-guard series lga/smd thin-film fuse –Accu-Guard® II Low Current
LGA Miniature 0201, 0402 and 0603 Size Thin-Film Fuses
FUSE PRE–ARC JOULE INTEGRALS VS PRE–ARC TIMEThe Important Information/Disclaimer is incorporated in the catalog where these specifications came from or available
online at www.kyocera-avx.com/disclaimer/ by reference and should be reviewed in full before placing any order.
TDS-FUSE-0002 | Rev 5– accu-guard series lga/smd thin-film fuse –5

Accu-Guard® II
SMD Thin-Film Fuse
Accu-Guard® II is a version of Accu-Guard® fuses for a wider range of current
and voltage ratings. Constructed on alumina substrates, Accu-Guard® IIfuses display superior electrical, mechanical and environmental properties.
Accu-Guard® II dimensions are standard 0402, 0603, 0805, 1206 and 0612
chip sizes, see page 2.

For F1206B and F0805B at -55°C is 107% of rating, at +25°C 100% of rating,at +85°C 93% of rating, at +125°C 90% of rating. For F0805B 2.50A and 3.00A
at +85°C 90% of rating, at +125°C 90% of rating.

ELECTRICAL SPECIFICATIONSFor F0612D at -55°C 107% of rating, at +25°C 100% of rating, at +85°C 80% of
rating, at +125°C 75% of rating.

Interrupting rating: 50A.
Insulation resistance: >20MΩ guaranteed (after fusing at rated voltage).

Operating temperature: -55°C to +125°C
Current carrying capacity:
For F0402E and F0603E at -55°C 107% of rating, at +25°C 100% of rating, at+125°C 80% of rating.

Type

F0402E

F0603E

F0805B

F1206B

F0612DPart Number

Current
RatingA

Resistance
10% x I rated, 25°C
Ω (max.)Voltage Drop
@1 x I rated, 25°C
mV (max.)

F0402E0R25FSTR
F0402E0R50FSTR
F0402E0R75FSTR
F0402E1R00FSTR
F0402E1R50FSTR
F0402E2R00FSTR
F0603E0R25FSTR
F0603E0R37FSTR
F0603E0R50FSTR
F0603E0R75FSTR
F0603E1R00FSTR
F0603E1R25FSTR
F0603E1R50FSTR
F0603E1R75FSTR
F0603E2R00FSTR
F0603E2R50FSTR
F0603E3R00FSTR
F0805B0R25FW/STR
F0805B0R50FW/STR
F0805B0R75FW/STR
F0805B1R00FW/STR
F0805B1R25FW/STR
F0805B1R50FW/STR
F0805B2R00FW/STR
F0805B2R50FW/STR
F0805B3R00FW/STR
F1206B0R25FW/STR
F1206B0R50FW/STR
F1206B1R00FW/STR
F1206B1R50FW/STR
F1206B2R00FW/STR
F1206B3R00FW/STR
F0612D4R00FWTR
F0612D5R00FWTR

0.25
0.50
0.75
1.00
1.50
2.00
0.25
0.375
0.50
0.75
1.00
1.25
1.50
1.75
2.00
2.50
3.00
0.25
0.50
0.75
1.00
1.25
1.50
2.00
2.50
3.00
0.25
0.50
1.00
1.50
2.00
3.00
4.00
5.00

0.650
0.250
0.200
0.130
0.060
0.040
0.650
0.450
0.250
0.200
0.130
0.090
0.060
0.050
0.040
0.035
0.030
0.750
0.350
0.270
0.220
0.170
0.120
0.080
0.060
0.050
0.750
0.350
0.180
0.120
0.080
0.050
0.040
0.025

220
180
180
160
140
120
220
220
180
180
160
140
140
120
120
100
100
280
280
280
280
280
240
220
220
220
280
280
240
240
220
220
260
200

Fusing Current(within 5 sec),
25°C
A
0.625
1.25
1.875
2.50
3.75
5.00
0.625
0.940
1.25
1.875
2.50
3.125
3.75
4.375
5.00
6.25
7.50
0.50
1.00
1.50
2.00
2.50
3.00
4.00
5.00
6.00
0.50
1.00
2.00
3.00
4.00
6.00
10
12.5

Pre-Arc
I2t @ 50A
A 2-sec

Rated
VoltageV

0.00005*
0.0003
0.003
0.008
0.03
0.06
0.00005*
0.00010.0003
0.003
0.008
0.01
0.03
0.04
0.06
0.12
0.25
0.00003*0.0002
0.001
0.003
0.007
0.010
0.030
0.050
0.10
0.000030.0002
0.003
0.010
0.030
0.10
0.10
0.25

32
32
32
32
32
32
32
32
32
32
32
32
32
32
32
32
32
63
63
63
63
63
63
63
63
63
63
63
63
63
63
63
32
32

*Current is limited to less than 50A at 32V due to internal fuse resistance.

6

The Important Information/Disclaimer is incorporated in the catalog where these specifications came from or available
online at www.kyocera-avx.com/disclaimer/ by reference and should be reviewed in full before placing any order.
TDS-FUSE-0001 | Rev 1– accu-guard series lga/smd thin-film fuse –Accu-Guard® II
SMD Thin-Film Fuse
ENVIRONMENTAL CHARACTERISTICS
Test

Conditions

Required

Solderability

Components completely immersed in a solder
bath at 235 ±5°C for 2 secs.

Terminations to be well tinned No
visible damage

Leach ResistanceCompletely immersed in a solder bath at 260±5°C for 60 secs

Dissolution of termination≤ 25% of area
∆R/R<10%

Storage

12 months minimum with components stored in“as received” packaging.

Good solderability

Shear

Components mounted to a substrate.
A force of 5N applied normal to the line joining
the terminations and in a line parallel to thesubstrate

No visible damage

Rapid Change of
Temperature

Components mounted to a substrate. 50 cycles-55° to +125°C.

No Visible damage∆R/R<10%Vibration

Components mounted to substrate.
50 cycles -55°C to +125°C.

No Visible damage∆R/R<10%Vibration

Components mounted to substrate.
50 cycles -55°C to +125°C.

No Visible damage∆R/R<10%

Tested as shown in diagram
3 mmDeflection

Bend

45mm

Load Life
F0805B, F1206B

45mm

25°C, rated current, 20,000 hrs.

No visible damage∆R/R<10%

No visible damage∆R/R<10%The Important Information/Disclaimer is incorporated in the catalog where these specifications came from or available
online at www.kyocera-avx.com/disclaimer/ by reference and should be reviewed in full before placing any order.
TDS-FUSE-0001 | Rev 1– accu-guard series lga/smd thin-film fuse –7

Accu-Guard® II
Lead-Free SMD Thin-Film Fuse
FUSE TIME – CURRENT CHARACTERISTICS FOR TYPE F0402E (TYPICAL)
10

1
2.0 A
1.5 A

10 -1
Pre Arc
T ime,
sec

1.0 A
10

0.75 A-2

0.5 A
0.25 A
10 -3

10 -4

10

-5

10 -6
0.1

1

10

100

Current, Amp

8

The Important Information/Disclaimer is incorporated in the catalog where these specifications came from or available
online at www.kyocera-avx.com/disclaimer/ by reference and should be reviewed in full before placing any order.
TDS-FUSE-0001 | Rev 1– accu-guard series lga/smd thin-film fuse –Accu-Guard® II
Lead-Free SMD Thin-Film Fuse
FUSE PRE-ARC JOULE INTEGRALS VS CURRENT FOR
TYPE F0402E (TYPICAL)
100
10
1

P reA rc
I 2 t,
A 2 s ec

10-1

2.0 A
10-2

1.5 A

10-3

1.0 A
10-4

0.7 5 A

10-5

0.5 A
0.2 5 A

10-6

0

10

20

30

40

50

60

C urrent, A m p

The Important Information/Disclaimer is incorporated in the catalog where these specifications came from or available
online at www.kyocera-avx.com/disclaimer/ by reference and should be reviewed in full before placing any order.
TDS-FUSE-0001 | Rev 1– accu-guard series lga/smd thin-film fuse –9Accu-Guard® II
Lead-Free SMD Thin-Film Fuse
FUSE PRE-ARC JOULE INTEGRALS VS PRE-ARC TIME FOR
TYPE F0402E (TYPICAL)

100

100

0

10
1

Pre Arc I2t,
A2sec

10

-1

10

-2

2.0 A
1.5 A

10

-3

10

-4

10

-5

1.0 A
0.75 A
0.5 A
0.25 A
10

-6
0

10

-6

10

-5

10

-4

10

-3

10

-2

10

-1

1

Pre -Arc Time, sec

10

The Important Information/Disclaimer is incorporated in the catalog where these specifications came from or available
online at www.kyocera-avx.com/disclaimer/ by reference and should be reviewed in full before placing any order.
TDS-FUSE-0001 | Rev 1– accu-guard series lga/smd thin-film fuse –10

Accu-Guard® II
Lead-Free SMD Thin-Film Fuse
FUSE TIME – CURRENT CHARACTERISTICS FOR
TYPE F0603E (TYPICAL)
10
3.0 A
2.5 A

1

2.0 A
1.75 A
1.5 A

10-1

1.25 A
1.0 A

P reA rc
Time,
s ec

0.7 5 A

10-2

0.5 A
0.37 5 A-3

10

0.2 5 A

10-4

10-5

10-6

0.1

1

10

100

C urrent, A m p

The Important Information/Disclaimer is incorporated in the catalog where these specifications came from or available
online at www.kyocera-avx.com/disclaimer/ by reference and should be reviewed in full before placing any order.
TDS-FUSE-0001 | Rev 1– accu-guard series lga/smd thin-film fuse –11

Accu-Guard® II
Lead-Free SMD Thin-Film Fuse
FUSE PRE-ARC JOULE INTEGRALS VS CURRENT FOR
TYPE F0603E (TYPICAL)
100

3.0A
2.5A

10

2.0A

1

1.75A

Pre-Arc I2t, A2sec

10-1

1.5A
1.25A

10-2

1.0A
-3

10

0.75A
0.5A

10-4

0.375A

10-5

0.25A

10-6

0

10

20

30

40

50

Current, Amp

12

The Important Information/Disclaimer is incorporated in the catalog where these specifications came from or available
online at www.kyocera-avx.com/disclaimer/ by reference and should be reviewed in full before placing any order.
TDS-FUSE-0001 | Rev 1– accu-guard series lga/smd thin-film fuse –60

Accu-Guard® II
Lead-Free SMD Thin-Film Fuse
FUSE PRE-ARC JOULE INTEGRALS VS PRE-ARC TIME FOR
TYPE F0603E (TYPICAL)
100
3.0A

10

2.5A
2.0A

1

1.75A

Pre Arc I2t,
A2sec

10

-1

10

-2

10

-3

10

-4

10

-5

10

-6

1.5A
1.25A
1.0A
0.75A
0.5A
0.375A
0.25A

10

-6

10

-5

10

-4

10

-3

10

-2

10

-1

1

10

Pre -Arc Time, sec

The Important Information/Disclaimer is incorporated in the catalog where these specifications came from or available
online at www.kyocera-avx.com/disclaimer/ by reference and should be reviewed in full before placing any order.
TDS-FUSE-0001 | Rev 1– accu-guard series lga/smd thin-film fuse –13

Accu-Guard® II
SMD Thin-Film Fuse
FUSE TIME - CURRENT CHARACTERISTICS FOR
TYPES F0805B AND F1206B (TYPICAL)
10

0.15A
0.25A
0.375A
0.50A
0.75A
1.00A
1.25A
1.5A
1.75A
2.0A
2.5A
3.0A

1

Pre-Arc Time, Seconds

10-1

10-2

10-3

10-4

10-5

10-6
0.1

1

10

100

Current, Amp

14

The Important Information/Disclaimer is incorporated in the catalog where these specifications came from or available
online at www.kyocera-avx.com/disclaimer/ by reference and should be reviewed in full before placing any order.
TDS-FUSE-0001 | Rev 1– accu-guard series lga/smd thin-film fuse –Accu-Guard® II
SMD Thin-Film Fuse
FUSE PRE-ARC JOULE INTEGRALS VS. CURRENT TIME FOR TYPES
F0805B AND F1206B (TYPICAL)
100
10

Pre-Arc I2t, A2sec

1
10-1
10-2
3.00A
2.50A
2.00A
1.50A
1.25A
1.00A
0.75A
0.50A
0.25A
0.15A

10-3
10-4
10-5
10-6

0

10

20

30

40

50

60

Current, Amp

The Important Information/Disclaimer is incorporated in the catalog where these specifications came from or available
online at www.kyocera-avx.com/disclaimer/ by reference and should be reviewed in full before placing any order.
TDS-FUSE-0001 | Rev 1– accu-guard series lga/smd thin-film fuse –15

Accu-Guard® II
SMD Thin-Film Fuse
FUSE PRE-ARC JOULE INTEGRALS VS. PRE-ARC TIME FOR TYPES
F0805B AND F1206B (TYPICAL)
100
10

Pre-Arc I2t, A2sec

1
10-1
10-2
3.00A
2.50A
2.00A
1.50A
1.25A
1.00A
0.75A
0.50A
0.25A
0.15A

10-3
10-4
10-5
10-6
10-7

10-6

10-5

10-4

10-3

10-2

10-1

Pre-Arc Time, Seconds

16

The Important Information/Disclaimer is incorporated in the catalog where these specifications came from or available
online at www.kyocera-avx.com/disclaimer/ by reference and should be reviewed in full before placing any order.
TDS-FUSE-0001 | Rev 1– accu-guard series lga/smd thin-film fuse –1

10Accu-Guard® II
SMD Thin-Film Fuse
FUSE TIME - CURRENT CHARACTERISTICS FOR TYPE
F0612D (TYPICAL)**Not recommended for new designs,
please contact factory10

1

Pre-Arc Tim e,Seconds

10-1

10-2

10-3

5.0A
4.0A

10-4

10-5

1

10

100

Curr
ent,
Am p

The Important Information/Disclaimer is incorporated in the catalog where these specifications came from or available
online at www.kyocera-avx.com/disclaimer/ by reference and should be reviewed in full before placing any order.
TDS-FUSE-0001 | Rev 1– accu-guard series lga/smd thin-film fuse –17

Accu-Guard® II
SMD Thin-Film Fuse
FUSE PRE-ARC JOULE INTEGRALS VS. PRE-ARC TIME
FOR TYPE F0612D (TYPICAL)**Not recommended for new designs,
please contact factory

1000

100

10

Pre-Arc I2t, A2sec

1

5.00A

10-1
4.00A
10-2

10-3

10-4

10-5
10-6

10-5

10-4

10-3

10-2

10-1

1

Pre-Arc Time, Seconds

18

The Important Information/Disclaimer is incorporated in the catalog where these specifications came from or available
online at www.kyocera-avx.com/disclaimer/ by reference and should be reviewed in full before placing any order.
TDS-FUSE-0001 | Rev 1– accu-guard series lga/smd thin-film fuse –10

Accu-Guard® II
SMD Thin-Film Fuse
FUSE PRE-ARC JOULE INTEGRALS VS. CURRENT FOR
TYPE F0612D (TYPICAL)*Not recommended for new designs,
please contact factory

1000

100

10

Pre-Arc i2t, A2sec

1
5.00A
10-1

4.00A

10-2

10-3

10-4

10-5

0

10

20

30

40

50

60

Current, Amp

The Important Information/Disclaimer is incorporated in the catalog where these specifications came from or available
online at www.kyocera-avx.com/disclaimer/ by reference and should be reviewed in full before placing any order.
TDS-FUSE-0001 | Rev 1– accu-guard series lga/smd thin-film fuse –19

Accu-Guard®
SMD Thin-Film Fuse Handling and Soldering
QUALITY & RELIABILITYCOMPONENT PAD DESIGN

Accu-Guard® series of fuses is based on established thin-film technology andmaterials used in the semiconductor industry.

Component pads must be designed to achieve good joints and minimize
component movement during soldering. Pad designs are given below for
both wave and reflow soldering.

•In-line Process Control: This program forms an integral part of the
production cycle and acts as a feedback system to regulate and control
production processes. The test procedures, which are integrated into the
production process, were developed after long research and are based on thehighly developed semiconductor industry test procedures and equipment.
These measures help KYOCERA AVX/Kyocera to produce a consistent andhigh yield line of products.
• Final Quality Inspection: Finished parts are tested for standard elecricalparameters and visual/mechanical characteristics. Each production lot is100% evaluated for electrical resistance. In addition, each production lot isevaluated on sample basis for:The basis of these designs are:a. Pad width equal to component width. It is permissible todecrease this to as low as 85% of component width but it
is not advisable to go below thisb. Pad overlap 0.5mm.
c. Pad extension 0.5mm for reflow. Pad extension about
1.0mm for wave soldering.

PREHEAT & SOLDERINGThe rate of preheat in production should not exceed 4°C/second. It is
recommended not to exceed 2°C/second Temperature differential frompreheat to soldering should not exceed 150°C. For further specific applicationor process advice, please consult KYOCERA AVX• Insulation resistance (post fusing)• Blow time for two times rated current• Endurance Test: 125°C, rated current, 4 hours

HAND SOLDERING & REWORKHANDLING AND SOLDERINGSMD chips should be handled with care to avoid damage or contaminationfrom perspiration and skin oils. The use of plastic tipped tweezers or
vacuum pick-ups is strongly recommended for individual components. Bulk
handling should ensure that abrasion and mechanical shock are minimized.
For automatic equipment, taped and reeled product is the ideal medium fordirect presentation to the placement machine.

Hand soldering is permissible. Preheat of the PCB to 100°C is required. The
most preferable technique is to use hot air soldering tools. Where a soldering
iron is used, a temperature controlled model not exceeding 30 watts
should be used and set to not more than 260°C. Maximum allowed time attemperature is 1 minute

COOLING
After soldering, the assembly should preferably be allowed to cool naturally.
In the event of assisted cooling, similar conditions to those recommended
for preheating should be used

REFLOW SOLDERINGCIRCUIT BROAD TYPE
All flexible types of circuit boards may be used
(e.g. FR-4, G-10).
For other circuit board materials, please consult factory.

Dimensions: millimeters (inches)
0402

WAVE SOLDERING
0603

0.8
(0.031)
2.1(0.083)3.1(0.122)0.8(0.031)1206
1.0(0.039)2.0(0.079)1.5(0.059)0.8(0.031)1.0(0.039)1.25(0.049)1.5(0.059)0612

2.0(0.079)1.6(0.063)1.25(0.049)3.1(0.122)5.0(0.197)0.6 (0.024)

3.1(0.122)1.25(0.049)1206

1.25(0.049)1.25(0.049)4.0(0.157)1.0(0.039)0.59(0.023)1.25(0.049)3.1(0.122)4.0(0.157)0.6 (0.024)
1.25(0.049)3.1(0.122)1.5(0.059)1.6(0.063)20

1.0(0.039)1.0(0.039)0.8(0.031)0612

1.5(0.059)0.6(0.024)1.0(0.039)3.0(0.118)0.6(0.024)0.85(0.033)0.59(0.023)0805

1.25(0.049)0.5(0.020)0805

0.85(0.033)
2.3(0.091)

0.5(0.020)0.6(0.024)

Dimensions: millimeters (inches)
0402

0603

0.6
(0.024)1.7(0.068)The Important Information/Disclaimer is incorporated in the catalog where these specifications came from or available
online at www.kyocera-avx.com/disclaimer/ by reference and should be reviewed in full before placing any order.
010319– accu-guard series lga/smd thin-film fuse –Accu-Guard®
SMD Thin-Film Fuse Handling and Soldering
RECOMMENDED SOLDERING PROFILESRECOMMENDED REFLOWSOLDERING PROFILECOMPONENTS WITH
SnPb TERMINATIONSRECOMMENDED REFLOWSOLDERING PROFILELEAD FREECOMPONENTS WITH
Sn100 TERMINATIONSCLEANING RECOMMENDATIONSSTORAGE CONDITIONS

Care should be taken to ensure that the devices are thoroughly cleaned offlux residues, especially the space beneath the device. Such residues mayotherwise become conductive and effectively offer a lousy bypass to thedevice. Verious recommended cleaning conditions (which must be optimized
for the flux system being used) are as follows:

Recommended storage conditions for Accu-Guard®
prior to use are as follows:
Temperature: 15°C to 35°C
Humidity: <65%
Air Pressure: 860mbar to1060mbar

Cleaning liquids........... i-propanol, ethanol, acetylacetone, water,and other standard PCB cleaning liquids.
Ultrasonic conditions...power - 20w/liter max.
frequency - 20kHz to 45kHz
Temperature................ 80°C maximum (if not otherwise limited bychosen solvent system).
TIME......................................5 minutes max.

The Important Information/Disclaimer is incorporated in the catalog where these specifications came from or available
online at www.kyocera-avx.com/disclaimer/ by reference and should be reviewed in full before placing any order.
010319– accu-guard series lga/smd thin-film fuse –21

Accu-Guard®
SMD Thin-Film Fuse Handling and Soldering
PACKAGING
Automatic Insertion Packaging
Tape & Reel: All tape and reel specifications are in compliance with EIA 481-1– 8mm carrier– Reeled quantities: Reels of 3,000 or 10,000 pieces
			(for F0402: 5,000 or 20,000 pieces)

G MAX.
B*
A

C
E

D*

FULL RADIUS
F*DRIVE SPOKES OPTIONALIF USED, ASTERISKEDDIMENSIONS APPLY.

REEL DIMENSIONS

millimeters (inches)

A(1)

B*

C

D*

E

F

G

180 + 1.0
(7.087 + 0.039)

1.5 min.
(0.059 min.)

13 ± 0.2(0.512 ± 0.008)

20.2 min.
(0.795 min.)50 min.
(1.969 min.)

9.4 ± 1.5
(0.370 ± 0.050)

14.4 max.
(0.567 max.)

Metric dimensions will govern.
Inch measurements rounded for reference only.
(1) 330mm (13 inch) reels are available.

E
D

F

10 PITCHESCUMULATIVETOLERANCE ON
TAPE 0.2
C

TOP
TAPE

W

B

A

L
P

CENTER LINESOF CAVITY

DIRECTION OF FEEDP = 4mm except 0402 where P = 2mm

CARRIER DIMENSIONS

millimeters (inches)

A

B

C

D

E

8.0 ± 0.3
(0.315 ± 0.012)

3.5 ± 0.05
(0.138 ± 0.002)

1.75 ± 0.1(0.069 ± 0.004)

2.0 ± 0.05
(0.079 ± 0.002)

4.0 ± 0.1
(0.157 ± 0.004)

F

Note: The nominal dimensions of the component compartment (W,L) are derived from the component size.

22

The Important Information/Disclaimer is incorporated in the catalog where these specifications came from or available
online at www.kyocera-avx.com/disclaimer/ by reference and should be reviewed in full before placing any order.
090518– accu-guard series lga/smd thin-film fuse –Accu-Guard®
Fuse Selection Guide
HOW TO CHOOSE THE CORRECT ACCU–GUARD FUSEFOR CIRCUIT PROTECTION
Correct choice of an Accu-Guard® fuse for a given application is fairly
straightforward. The factor of pre-arc l2t, however, requires clarification. The
proper design for pre-arc l2t is presented by way of example

DESIGN PARAMETERS
1. Operating Temperature
The Accu-Guard® is specified for operation in the temperature rangeof -55°C to +125°C. Note, however, that fusing current is sensitive totemperature this means that the fuse must be derated or uprated atcircuit temperatures other than 25°C:

Environmental
Temperature

In order to design for current pulses, the concept of fuse pre-arc Joule integral,
I2t, must be understood. Fuse current rating is defined by the requirementthat 2 x Ir or 2.5 x Ir (depending on fuse type) will cause actuation in t<5seconds. This rating does not indicate how the fuse will react to very highcurrents of very short duration. Rather, the fusing characteristic at very highcurrents is specified by I2t-t curves (or I2t-I).

Accu-Guard®
Current Carrying Capacity*
F0402G
F0603G
F0402E,
F0603E

F0805B,
F1206A,
F1206B

F0805B
2.50A &
3.00A

F0603C

F0612D-55°C to -11°C

1.07 x IR

1.07 x IR

1.07 x IR

1.07 x IR

1.07 x IR-10°C to 60°C

IR

IR

IR

IR

IR

61°C to 100°C

0.85 x IR

0.93 x IR

0.90 x IR

0.90 x IR

0.80 x IR

101°C to 125°C

0.80 x IR

0.90 x IR

0.90 x IR

0.75 x IR

0.75 x IR

5. Switch-on and Other Pulse Current
Many circuits generate a large current pulse when initially connected to
power. There are also circuits which are subject to momentary current pulses
due to external sources; telephone line cords which are subject to lightninginduced pulses are one example. These current pulses must be passed by
the fuse without causing actuation. These pulses may be so large that they
are the determining factor for choosing the Accu-Guard® current rating; notnecessarily steady state current.

I2t expresses the amount of energy required to actuate the fuse. Total
I²t expresses the total energy which will be passed by the fuse until total
cessation of current flow. Pre-arc I²t expresses that energy required to cause
large irreversible damage to the fuse element (Total I²t = pre-arc I²t + arc I²t).
If the Joule integral of the switch-on pulse is larger than the fuse pre-arc I²t,
nuisance actuation will occur.

*As a function of nominal rated current, lR.

In order to choose the proper Accu-Guard® current rating for a given
application, it is necessary to calculate the I²t Joule integral of the circuit
switch-on and other current pulses and compare them to the Accu-Guard®
I²t-t curves. An Accu-Guard® fuse must be chosen such that the pulse I²t is
no more than 50% of the pre-arc I²t of the prospective fuse.

2. Circuit Voltage
Maximum Voltage: Accu-Guard® is specified for circuits of up to rated
voltage. Accu-Guard® will successfully break currents at higher voltages as
well, but over voltage may crack the fuse body.

Pre-arc I²t of the Accu-Guard® fuses is well characterized; I²t-t and I²t-I graphs
are in this catalog. The problem is calculating the I²t of the circuit current
pulses. This concept is not familiar to most engineers. Correct calculation ofpulse Joule integral and subsequent choice of Accu-Guard® current rating is
illustrated by way of the attached examples.

Minimum Voltage: Accu-Guard® cannot be used in circuits with voltage ofabout 0.5V and less. The internal resistance of the fuse will limit the fault
current to a value which will prevent reliable actuation of the fuse (<2 x rated
current).

3. Maximum Fault Current
Accu-Guard® is fully tested and specified for fault currents up to 50A. AccuGuard® will successfully break currents above 50A, but such current may
crack the fuse body or damage the fuse terminations.
4. Steady-State Current
Accu-Guard® is specified to operate at least 4 hours at rated current without
fusing (25°C). Engineering tests have shown that F0805B and F1206A/B
Accu-Guard® will in fact operate at least 20,000 hours at rated current without
fusing (25°C).

The Important Information/Disclaimer is incorporated in the catalog where these specifications came from or available
online at www.kyocera-avx.com/disclaimer/ by reference and should be reviewed in full before placing any order.
010319– accu-guard series lga/smd thin-film fuse –23

Accu-Guard®
Fuse Selection Guide
DESIGNING FOR CURRENTPULSE SITUATIONS

2. Triangular current pulse
The Joule integral for triangular pulse is [(Imax)2 x t] /3, see Fig. 2a.

1. Sine wave current pulse
The Joule integral for sine wave pulse is[(Imax)2 x t] /2

l max.

see Fig. 1a.

l max.

t
Fig. 2a. Triangular pulse parameters for joule integral calculation,
example #2.

t

Thus, for the current pulse in Figure 2b, the Joule integral is[(1.5A2 x 3 x 10-3 sec]/3 = 2.25 x 10-3 A2sec

Fig. 1a. Sine wave pulse paramerters for Joule integral
calculation, example #1.

2 msec/div

Thus, for the current pulse in FIgure 1b, the Joule integral is[(4.8A)2 x 7.7 x 10-6 sec]/2 = 8.9 x 10-5 A2 sec
10 sec/div

0.5A/div

1A/divFig. 2b. Triangular pulse, example #2.

Fig. 1b. Triangular pulse, example #1.
The pulse duration is 7.7μsec. We must find a fuse that can absorb atleast 8.9 x 10-5 x 2 = 1.8 x 10-4 A2sec Joule integral within 7.7μsec without
actuation. According to the l2t graph on page 6, pre-arching Joule intergral is
2.3x10-4 A2sec for the 0.5A fuse, which is slightly more than needed. The next
lower rating (0.375A), has only 6x10-5 A2 sec, which is not enough. Therefore,
0.5A fuse should be chosen for this application, see Figure 1c.

The pulse duration is 3 msec. In the l2t graph on page 6, pre-arcing Jouleintergral for 3 msec pulse is 4 x 10-3A2sec for the 0.5A fuse (not enough) and2 x 10-2 for the 0.75A fuse (more than enough). Therefore, 0.75A fuse should
be chosen for this application, see Figure 2c.
FUSE PRE-ARCING JOULE INTEGRALS
vs. PRE-ARCING TIME
100

PRE-ARCING TIME l2t, A2 sec

10
1

FUSE PRE-ARCING JOULE INTEGRALS
vs. PRE-ARCING TIME
100

10-1

0.75A

10-2
10-4

10

10-5
10-7

1

10-6

10-1
10-2
10-4

x
10-6

10-5 10-4 10-3 10-2
PRE-ARCING TIME, sec

10-1

10-5 10-4 10-3 10-2
PRE-ARCING TIME, sec

10-1

1

10

Fig. 1c. Choice of 0.5A fuse, example #1.
––––– Pre-arcing l2t-------- Maximum l2t deisgn rulex l2t for sample current pulse

241Fig. 2c. Choice of 0.75A fuse, example #2.
––––– Pre-arcing l2t-------- Maximum l2t deisgn rulex l2t for sample current pulse

0.5A

10-3
10-5
10-7

x

10-3

PRE-ARCING TIME l2t, A2 sec

The Important Information/Disclaimer is incorporated in the catalog where these specifications came from or available
online at www.kyocera-avx.com/disclaimer/ by reference and should be reviewed in full before placing any order.
011419– accu-guard series lga/smd thin-film fuse –10

Accu-Guard®
Fuse Selection Guide
DESIGNING FOR CURRENT PULSE SITUATIONS (CONT.)
3. Trapezoidal current pulse
The Joule integral for a trapezoidal pulse is

4. Lightning strike
A Lightning strike pulse is shown in Figure 4a. After an initial linear
rise, the current declines exponentially[(I2max+I2min+Imax * Imin) / 3] x t
see Fig. 3a.

l max.
0.51 max.

l max.
l min.

t0.5
Fig. 4a. Lightning pulse parameters for Joule
integral calculation, example #4tFig. 3a. Trapezoidal pulse paramerters for Joule
integral calculation, example #3

Joule integral for the linear current rise is calculated as for a triangularpulse, see example #2
The Joule integral for the exponential decline islmax2 x t0.5 x (-1/2ln 0.5) = 0.72(lmax)2 x t0.5
Thus, for the sample lightning strike pulse in Figure 4b, thetotal Joule integral is:(25A)2 x 2 x 10-6sec/3+0.72 x (25A)2 x 10 x 10-6sec = 4.92 x 10-3A2sec

Thus, for current pulse in Figure 3b, the Joule integral is:{[(0.56A)2+ (1A)2 +0.56A x 13A] / 3 } x 3 x 10-3s = 1.9 x 10-3A2sec

10 sec/div

0.5 msec/div

5A/div

0.5A/div

Fig. 4b. Lightning strike pulse, example #4.
Fig. 3b. Trapezoidal pulse, example #3

According to the l2t graph on page 6, the 0.5A fuse should bechosen for this application, see Figure 3c.

For practical calculations, the duration of exponential decline may be
assumed to be 3t0.5, because within this time 98.5% of the pulse energy isreleased. Thus, the total pulse duration in this example is 30 μsec, and the
1.25A fuse should be chosen for this application, see Figure 4c.

FUSE PRE-ARCING JOULE INTEGRALS
vs. PRE-ARCING TIME
100

FUSE PRE-ARCING JOULE INTEGRALS
vs. PRE-ARCING TIME

PRE-ARCING TIME l2t, A2 sec

100

10

10

1

1

10-1

10-1

10-2

0.50A

10-3

1.25A

10-2

x

x

10-3

10-4
10-5
10-7

PRE-ARCING TIME l2t, A2 sec

10-4
10-6

10-5 10-4 10-3 10-2
PRE-ARCING TIME, sec

10-1

1

10-5
10-7

10

Fig. 3c. Choice of 0.75A fuse, example #3.
––––– Pre-arcing l2t-------- Maximum l2t deisgn rulex l2t for sample current pulse

10-6

10-5 10-4 10-3 10-2
PRE-ARCING TIME, sec

10-1

1

10

Fig. 4c. Choice of 0.5A fuse, example #4.
––––– Pre-arcing l2t-------- Maximum l2t deisgn rulex l2t for sample current pulse

The Important Information/Disclaimer is incorporated in the catalog where these specifications came from or available
online at www.kyocera-avx.com/disclaimer/ by reference and should be reviewed in full before placing any order.
011419– accu-guard series lga/smd thin-film fuse –25

Accu-Guard®
Fuse Selection Guide
DESIGNING FOR CURRENT PULSE SITUATIONS (CONT.)
5. Complex current pulse
If the pulse consists of several waveforms, all of them should be evaluatedseperately, and then the total Joule integral should be calculated as well.

6. Switch-on pulse and steady-state current
In Figure 6a, the switch-on pulse is a triangle pulse with a 5.1 x 10-3
A2sec Joule integral of 5 msec duration; the 0.75A fuse will meetthis requirement, see Figure 6b.

200 sec/div

2 msec/div

2A/divFig. 5a. Complex pulse, example #5

0.5A/div

Fig. 6a. Switch-on pulse and steady-state current,
example #6

In Figure 5a, the Joule integral for the first triangle is [(4.67A)
x 294 x 10-6sec]/3=2.14 x 10-3 A2sec
and 0.75A fuse should meet this condition, see Figure 5b.

2

FUSE PRE-ARCING JOULE INTEGRALS
vs. PRE-ARCING TIMEFUSE PRE-ARCING JOULE INTEGRALS
vs. PRE-ARCING TIME

100

100
10

PRE-ARCING TIME l2t, A2 sec

1
10-1

10

0.75A

10-2

1

x

10-3

10-1

10-4

0.75A
x x

10-2
10-3

10-5
10-7

10-4
10-5
10-7

PRE-ARCING TIME l2t, A2 sec

10-6

10-5 10-4 10-3 10-2
PRE-ARCING TIME, sec

10-1

1

10-5 10-4 10-3 10-2
PRE-ARCING TIME, sec

10-1

10

The steady-state current is 0.5A, and 1A fuse is typically recommended
to meet the steady-state condition. Based on steady-state current, the1A fuse should be chosen for this application.

The Joule integral for the second triangle is[(5.33A)2 x 269 x 10-6sec]/3 = 2.55 x 10-3 A2sec, and 0.75A fuse issuitable for this case also, see Figure 5b.
However, for the whole pulse, the Joule integral is 4.7 x 10-3 A2sec,
and the total duration is 563 μsec. For the 0.75A fuse, the Joule
integral is only 8.6 x 10-3 A2sec for this pulse duration, so 1A fuseshould be chosen for this application, see Figure 5b.

26

1Fig. 6b. Choice of 0.75A fuse, example #6.
––––– Pre-arcing l2t-------- Maximum l2t deisgn rulex l2t for sample current pulse

10

Fig.5b. Choice of fuse, example #5––––– Pre-arcing l2t-------- Maximum l2t deisgn rulex l2t for sample switch-on pulse

10-6

The Important Information/Disclaimer is incorporated in the catalog where these specifications came from or available
online at www.kyocera-avx.com/disclaimer/ by reference and should be reviewed in full before placing any order.
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