Littelfuse TMOV 25S Varistor Series - Manual (Page 4)

© 2013 Littelfuse, Inc. 218
Revised: May 8, 2013
Varistor Products
TMOV ® 25S Varistor Series
Specifications are subject to change without notice.
Please refer to www.littelfuse.com/series/tmov.html for current information.
Radial Lead Varistors > TMOV ® 25S Series
Pulse Rating Curve
Wave Solder Profile
Because the TMOV ® 25S Series contains a thermally
responsive device, care must be taken when soldering
the device into place. Two soldering methods are possible.
Firstly, hand soldering: We recommend the use of pliers
to heat-sink the leads of the device. Secondly, wave-
soldering: This is a strenuous process requiring pre-heat
stages to reduce the stresses on devices.
It is critically important that all preheat stage and the
solder bath temperatures are rigidly controlled. The
recommended solder for the TMOV
® Series is a 62/36/2
(Sn/Pb/Ag), 60/40 (Sn/Pb) or 63/37 (Sn/Pb). Littelfuse also
recommends an RMA solder flux. SAC solders (SnAgCu)
are recommended for Lead-free applications.
Soldering Profile
0
50
100
150
200
250
300
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
TIME (MINUTES)
MAXIMUM WAVE 260ºC
PREHEAT
TEMPERA
TURE (ºC)
1
2
∞
15
10
2
10 3
1
10
100
1000
10000
100000
10 100 1000 10000
Impulse Duration (μsecs)
10 4
10 5
10
6
Sur
g
e
Cur
rent (A)
Number of Pulses
Figure 4
Figure 5