TMOV25SP385M Littelfuse Inc, TMOV25SP385M Datasheet - Page 16

• 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

------------ -
c
the field lowered barrier, and is thermally activated, at least
above about 25ºC. For semiconductor abrupt P-N junction
diodes. The relationship is:
Where:
(V
(V) = applied voltage,
(q) = electron charge,
(es) = semiconductor permittivity and
(N) = carrier concentration.
From this relationship the ZnO carrier concentration, N,
was determined to be about 2 x 10
In addition, the width of the depletion layer was calculated
to be about 1000 Angstrom units. Single junction studies
also support the diode model.
Figure 5, shows an energy band diagram for a ZnO-grain
boundary-ZnO junction . The left-hand grain is forward
biased, V
depletion layer widths are X
barrier heights are f
is f
f
increase in conduction.
The barrier height f
measured as a function of applied voltage, and is
presented in Figure 6. The rapid decrease in the barrier at
high voltage represents the onset of nonlinear conduction.
2
R
1
FIGURE 4. CAPACITANCE-VOLTAGE BEHAVIOR OF
n
b
is increased, leading to a lowering of the barrier and an
2
O
) = barrier voltage,
/cm
. As the voltage bias is increased, f
(10
4
14
L
, and the right side is reverse biased to V
4
3
2
)
VARISTOR RESEMBLES A SEMICONDUCTOR
ABRUPT-JUNCTION REVERSED BIASED DIODE
Nd ~ 2 x 10
0
L
------ -
C
L
1
of a low voltage varistor was
2
and f
17
=
0.4
/cm
2 V
------------------------- -
(
V A PER BOUNDARY
R
q sN
3
. The zero biased barrier height
b
L
+
and X
V
)
0.8
17
R
, and the respective
per cm
L
is decreased and
3
.
1.2
R
. The
Revision: November 5, 2009
Varistor Products
12
Transport mechanisms in the nonlinear region are very
complicated and are still the subject of active research.
Most theories draw their inspiration from semiconductor
transport theory and is not covered in detail in this docu-
ment.
FIGURE 5. ENERGY BAND DIAGRAM OF A
FIGURE 6. THERMAL BARRIER vs APPLIED VOLTAGE
1.0
0.8
0.6
0.4
0.2
0
0
E
E
E
E
C
V
f
I
ZnO-GRAINBOUNDARY-ZnO JUNCTION
V
L
4
L
X
Please refer to www.littelfuse.com for current information.
L
VOLTAGE (V)
Specifications are subject to change without notice.
0 B
8
0
X
R
R
F
12
V
R
©2009 Littelfuse, Inc.
16