Littelfuse 438 User Manual

Page 1

Surface Mount Fuses

Ceramic Fuse > 438 Series

438 Series – 0603 Fast-Acting Fuse

Description

The 438 Series is a 100% Lead-free, RoHS compliant and Halogen-free fuse series designed speciﬁcally to provide over-current protection to circuits that operate under high working ambient temperature up to 150ºC.

The general design ensures excellent temperature stability and performance reliability.

The high I²t values which is typical in the Littelfuse Ceramic Fuse family ensure high inrush current withstand capability.

Features

Agency Approvals

AGENCY AGENCY FILE NUMBER AMPERE RANGE

E10480 0.250A – 6A

LR29862 0.250A – 6A

Electrical Characteristics for Series

% of Ampere

Rating

100% 0.250A – 6A 4 Hours, Minimum 250% 0.250A – 6A 5 Seconds, Maximum

Ampere Rating Opening Time at 25ºC

• OperatingTemperature

from -55ºC to +150ºC

• 100%Lead-free,RoHS

compliant and Halogenfree

Applications

• HandheldElectronics

• LCDDisplays

• BatteryPacks

Additional Information

Datasheet

• Suitableforbothleaded

and lead-free reﬂow / wave soldering

• HardDiskDrives

• SDMemoryCards

Resources

Samples

Electrical Speciﬁcations by Item

Ampere

Rating

0.375 .375 63VDC 1.247 0.0041 0.488 0.183 x x

Notes:

1. AC Interrupting Rating tested at rated voltage with unity power factor. DC Interrupting Rating tested at rated voltage with time constant < 0.8 msec.

2. Nominal Resistance measured with < 10% rated current.

3. Nominal Melting I²t measured at 1 msec. opening time.

4. Nominal Voltage Drop measured at rated current after temperature has stabilized.

Amp

Code

(A)

0.25 .250 63VDC

0.5 .500 63VDC 0.829 0.0100 0.486 0.243 x x

0.75 .750 63VDC 0.466 0.0281 0.378 0.284 x x 1 0 01. 63VDC 0.310 0.0593 0.351 0.351 x x

1.25 1.25 63VDC 0.200 0.0510 0.365 0.456 x x

1. 5 01.5 63VDC 0.174 0.0902 0.368 0.552 x x

1.75 1.75 63VDC 0.125 0.1440 0.360 0.540 x x 2 002. 32

2.5 02.5 32 0.0324 0.1977 0.095 0.238 x x 3 003. 32 0.0252 0.2922 0.093 0.279 x x

3.5 03.5 32 0.0203 0.4752 0.082 0.287 x x 4 004. 32 0.0169 0.6920 0.079 0.316 x x 5 005. 32 0.0113 0.7398 0.074 0.370 x x 6 006. 24 50A @ 24VDC/12VAC 0.0087 1.3838 0.072 0.432 x x

Max.

Voltage

Rating (V)

Interrupting Rating

50A @ 63VDC 50A @ 32VAC

50A @ 32VDC/12VAC

Nominal

Resistance

(Ohms)

2.024 0.0017 0.550 0.138 x x

0.051 0.1490 0.107 0.214 x x

Melting I2t

Nominal

(A2Sec.)

Nominal Voltage

Drop At Rated

Current (V)

Devices designed to carry rated current for 4 hours minimum. It is recommended that devices be operated continuously at no more than 80% rated current. See “Temperature Rerating Curve”for additional rerating information.

Devices designed to be mounted with marking code facing up.

Nominal Power

Dissipation At

Rated Current (W)

Agency Approvals

Page 2

Surface Mount Fuses

Ceramic Fuse > 438 Series

Temperature Rerating Curve

140

120

100

PERCENT OF RATING

-65 -45 -25 -5 15 35 55 75 95 115 135 155

TEMPERATURE (°C)

Note:

1. Rerating depicted in this curve is in addition to the standard rerating of 20% for continuous operation.

Example: For continuous operation at 75 degrees celsius, the fuse should be rerated as follows:

I = (0.80)(0.85)I

RAT

= (0.68)I

RAT

Average Time Current Curves

.250A

.750A

.375A

.500A

CURRENT IN AMPERES

TIME IN SECONDS

0.001

100

0.1

0.01

0.1

1.25A

2.5A

3.5A

1.5A

1.75A

10 100

Soldering Parameters

Reﬂow Condition Pb – free assembly

- Temperature Min (T

Pre Heat

- Temperature Max (T

- Time (Min to Max) (ts) 60 – 180 seconds

Average Ramp-up Rate (Liquidus Temp (T

) to peak)

to TL - Ramp-up Rate 5°C/second max.

S(max)

Reﬂow

- Temperature (TL) (Liquidus) 217°C

- Temperature (tL) 60 – 150 seconds

Peak Temperature (TP) 260

Time within 5°C of actual peak Temperature (t

)

Ramp-down Rate 6°C/second max.

Time 25°C to peak Temperature (T Do not exceed 260°C

Wave Soldering 260°C, 10 seconds max.

) 150°C

s(min)

) 200°C

s(max)

3°C/second max.

+0/-5

°C

10 – 30 seconds

) 8 minutes max.

Temperature

S(max)

S(min)

time to peak temperature

Preheat

(t 25ºC to peak)

Ramp-up

Critical Zone

to T

Ramp-down

Time

Speciﬁcations are subject to change without notice.

Revised: 12/19/13

Page 3

Surface Mount Fuses

Ceramic Fuse > 438 Series

Product Characteristics

Body: Advanced Ceramic

Materials

Terminations: Ag / Ni / Sn (100% Lead-free) Element Cover Coating: Lead-free Glass

Moisture Sensitivity Level

IPC/JEDEC J-STD-020C, Level 1

Solderability IPC/EIC/JEDEC J-STD-002B, Condition B

Humidity MIL-STD-202, Method 103B, Conditions D

Resistance to Solder Heat

MIL-STD-202, Method 210F, Condition B

Dimensions

0.530 +/- 0.150

[0.021 +/- 0.006]

0.85 ± 0.150

[0.033 ± 0.006]

0.502 ± 0.080

[0.020 ± 0.003]

0.432 +/- 0.150

[0.017 +/- 0.006]

1.54 ± 0.150

[0.061 ± 0.006]

Moisture Resistance MIL-STD-202, Method 106G

Thermal Shock

Mechanical Shock

MIL-STD-202, Method 107G, Condition B-3

MIL-STD-202, Method 213B, Condition A

Vibration MIL-STD-202, Method 201A

Vibration, High Frequency

Dissolution of Metallization

MIL-STD-202, Method 204D, Condition D

IPC/EIC/JEDEC J-STD-002B, Condition D

Terminal Strength IEC 60127-4

Part Marking System

Amp Code Marking Code

.250 D .375 E .500 F .750 G

0 01. H

1.25 J

01. 5 K

1.75 L

002. N

02.5 O

003. P

03.5 R

004. S

005. T

006. U

0.60

[0.024]

1.00

[0.039]

0.74

[0.029]

Part Numbering System

SERIES

AMP CODE

1.94

[0.076]

Packaging

Packaging Option Packaging Speciﬁcation Quantity

8mm Tape and Reel EIA-481, IEC 60286, Part 3 3000 WR

0438 005. W R

PACKING CODE

R = Reel Pack

QUANTITY CODE

W = 3000 pcs

Quantity &

Packaging Code