Introduction to Circuit Protection

Introduction to Circuit Protection

Transientology

62

© 2009 Littelfuse, Inc.

Specifications are subject to change without notice.

Surface Mount Fuses

452/454 Series

Please refer to www.littelfuse.com/series/452.html

or /454.html for current information.

Average Time Current Curves

Reflow Condition

Pb – Free assembly

Pre Heat

-Temperature Min (T

-Temperature Max (T

-Time (Min to Max) (t

60 – 120 secs

Average ramp up rate (LiquidusTemp

(T

T

Reflow

-Temperature (T

-Temperature (t

60 – 90 seconds

PeakTemperature (T

Time within 5°C of actual peak

Temperature (t

20 – 40 seconds

Ramp-down Rate

Time 25°C to peakTemperature (T

8 minutes max.

Do not exceed

Wave Soldering Parameters

Temperature,

Soldering Parameters

Temperature Rerating Curve

Note:

continuous operation.

Time

25

time to peak temperature

(t 25ºC to peak)

Ramp-down

Ramp-up

Preheat

Critical Zone

0.01

0.1

1

10

100

0.1

1

10

100

1000

CURRENT IN AMPS