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©2006 Littelfuse

250R Series

Specifications are subject to change without notice.



Electronics Designers Guide

Radial Leaded

Environmental Specifications

Operating/Storage

Temperature

-40°C to +85°C

Maximum Device Surface

Temperature in Tripped State

125°C

Passive Aging

65°C/85°C, 1000 hours

Humidity Aging

+85°C, 85%R.H. 1000 hours

Thermal Shock

MIL-STD-202F Method 107G

+125°C to -55°C 10 times

Solvent Resistance

MIL-STD-202, Method 215F

Physical Specifications

Lead Material

Tin-plated copper

Soldering

Characteristics

Solderability per MIL-STD-202,

Method 208E

Insulating Material

Cured, flame retardant epoxy polymer

meets UL94V-0 requirements.

Device Labeling

Marked with LF, voltage, current rating,

and date code.

Soldering Parameters - Solder Reflow

Condition

Reflow

Peak Temp/ Duration Time

260°C > 5 Sec

> 220°C

30 Sec ~ 60 Sec

Preheat 160°C ~ 190°C

60 Sec ~ 90 Sec

Storage Condition

0°C~35°C, < 70%RH

• Recommended reflow methods: IR, vapor phase oven, hot

air oven, N

• Devices are not designed to be wave soldered to the

bottom side of the board.

• Devices can be cleaned using standard industry methods

and solvents.

Note: If reflow temperatures exceed the recommended

profile, devices may not meet the performance

requirements.

Preheating

160

190

220

260

0

30 to 60

Soldering

Cooling

120

60 to 90

Time(s)

Soldering Parameters - Wave Soldering

Condition

Wave Soldering

Peak Temp/ Duration Time

260°C < 5 Sec

> 220°C

2 Sec ~ 20 Sec

Preheat 140°C ~ 180°C

180 Sec ~ 210 Sec

Storage Condition

0°C~35°C < 70%RH

• Recommended soldering methods: heat element oven or

N

• Devices are designed to be wave soldered to the bottom

side of the board.

• Devices can be cleaned using standard industry methods

and solvents.

• This profile can be used for lead-free device

Note: If soldering temperatures exceed the recommended

profile, devices may not meet the performance

requirements.

Preheating

160

190

220

260

0

2 to 5

Soldering

Cooling

20-30

180 to 210

Time(s)