Introduction to Circuit Protection

Introduction to Circuit Protection

Transientology

30

© 2009 Littelfuse, Inc.

Specifications are subject to change without notice.

Surface Mount Fuses

Thin Film > 1206 Size > Very Fast-Acting > 466 Series

466 Series

Please refer to www.littelfuse.com/series/466.html for current information.

Average Time Current Curves

CURRENT IN AMPERES

0.01

0.1

0.1

1

1

10

100

10

100

0.001

reflow condition

Pb – free assembly

pre Heat

-Temperature min (T

150°C

-Temperature max (T

200°C

-Time (min to max) (t

60 – 180 seconds

Average ramp-up rate (liquidusTemp

(T

5°C/second max.

T

5°C/second max.

reflow

-Temperature (T

217°C

-Temperature (t

60 – 150 seconds

peakTemperature (T

Time within 5°c of actual peak

Temperature (t

20 – 40 seconds

ramp-down rate

5°C/second max.

Time 25°c to peakTemperature (T

8 minutes max.

Do not exceed

260°C

Soldering Parameters

Temperature Rerating Curve

Wave Soldering

260°C, 10 seconds max.

Note:

1. Rerating depicted in this curve is in addition to the standard rerating of 25% for

continuous operation.

Example:

For continuous operation at 70 degrees celsius, the fuse should be rerated as follows:

I = (0.75)(0.80)I

2. The temperature derating curve represents the nominal conditions. For questions

abouttemperaturederatingcurve,pleaseconsultLittelfusetechnicalsupportfor

assistance.

Time

25

time to peak temperature

(t 25ºC to peak)

Ramp-down

Ramp-up

Preheat

Critical Zone