TMOV25SP385M Littelfuse Inc, TMOV25SP385M Datasheet - Page 71

• Manufacturer Part Number: TMOV25SP385M
• Description: TMOV VARISTOR PB FREE 25S
• Manufacturer: Littelfuse Inc
• Series: iTMOV®r

Specifications of TMOV25SP385M

• Varistor Voltage: 682V
• Current-surge: 20kA
• Number Of Circuits: 1
• Maximum Ac Volts: 385VAC
• Energy: 430J
• Package / Case: Disc 25mm 3-Lead
• Suppressor Type: Varistor
• Peak Surge Current @ 8/20µs: 20000A
• Varistor Case: 25mm DISC
• Clamping Voltage Vc Max: 1010V
• Peak Energy (10/1000us): 430J
• Voltage Rating Vdc: 682V
• Voltage Rating Vac: 385V
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Maximum Dc Volts: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

©2009 Littelfuse, Inc.
Specifications are subject to change without notice.
Please refer to www.littelfuse.com/series/sm7.html for current information.
Lead (Pb) Soldering Recommendations
The principal techniques used for the soldering of
components in surface mount technology are IR Re-flow
and Wave soldering. Typical profiles are shown on the right.
The terminals of SM7 series devices are tin plated copper,
and the recommended solder is 62/36/2 (Sn/Pb/Ag), 60/40
(Sn/Pb) or 63/37 (Sn/Pb). Littelfuse also recommends an
RMA solder flux.
Wave soldering is the most strenuous of the processes.
To avoid the possibility of generating stresses due to
thermal shock, a preheat stage in the soldering process
is recommended, and the peak temperature of the solder
process should be rigidly controlled.
When using a reflow process, care should be taken to
ensure that the SM7 chip is not subjected to a thermal
gradient steeper than 4 degrees per second; the ideal
gradient being 2 degrees per second. During the soldering
process, preheating to within 100 degrees of the solder's
peak temperature is essential to minimize thermal shock.
Once the soldering process has been completed, it is
still necessary to ensure that any further thermal shocks
are avoided. One possible cause of thermal shock is hot
printed circuit boards being removed from the solder
process and subjected to cleaning solvents at room
temperature. The boards must be allowed to cool gradually
to less than 50ºC before cleaning.
Lead–free (Pb-free) Soldering Recommendations
The terminals of SM7 series devices are tin plated copper,
and the recommended Lead-free solder is 96.5/3.0/0.5
(SnAgCu) with an RMA flux, though there is a wide
selection of pastes and fluxes available that should be
compatible.
The reflow profile must be constrained by the maximums
in the Lead–free Reflow Profile. For Lead–free Wave
soldering, the Wave Solder Profile still applies.
Note: the Lead–free paste, flux and profile were used for
evaluation purposes by Littelfuse, based upon industry
standards and practices. There are multiple choices of all
three available, it is advised that the customer explores the
optimum combination for their process as processes vary
considerably from site to site.
Varistor Products
Surface Mount Varistors > SM7 Series
Revision: November 5, 2009
67
Figure 7
Figure 8
Figure 9
Reflow Solder Profile
Wave Solder Profile
Lead–free Re-flow Solder Profile
300
250
200
150
100
250
200
150
100
300
250
200
150
100
50
50
50
0
0
0
0.0
0
0
0.5
0.5
MAXIMUM TEMPERATURE 250˚C,
TIME WITHIN 5˚C OF PEAK
20 SECONDS MAXIMUM
1.0
PREHEAT ZONE
PREHEAT ZONE
1.0
1.0
PREHEAT DWELL
FIRST PREHEAT
2.0
MAXIMUM TEMPERATURE
1.5
1.5
TIME (MINUTES)
TIME (MINUTES)
MAXIMUM WAVE 260°C
TIME (MINUTES)
RAMP RATE
<3˚C/s
3.0
2.0
230°C
2.0
SECOND PREHEAT
RAMP RATE
<2°C/s
2.5
4.0
2.5
ABOVE 183°C
3.0
SECONDS
40-80
5.0
60 - 150 SEC
3.0
> 217˚C
3.5
SM7 Series Varistor
6.0
3.5
4.0
4.0
4.5
7.0