Varistor Products
70
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LA Varistor Series
Line Voltage Operation, Radial Lead
Device Ratings and Specifications (Continued)
Power Dissipation Ratings
Should transients occur in rapid succession, the average power dissipation
is the energy (watt-seconds) per pulse times the number of pulses per
second. The power so developed must be within the specifications shown
on the Device Ratings and Specifications table for the specific device.The
operating values of a MOV need to be derated at high temperatures as
shown in Figure 1. Because varistors only dissipate a relatively small
amount of average power they are not suitable for repetitive applications
that involve substantial amounts of average power dissipation.
V660LA10 10 660L 660 850 70 2500 940 1210 1820 25 70
V660LA50A 14 660L50 660 850 140 4500 940 1210 1820 50 200
V660LA100B 20 660L100 660 850 250 6500 940 1100 1650 100 400
V1000LA80A 14 1000L80 1000 1200 220 4500 1425 1800 2700 50 130
V1000LA160B 20 1000L160 1000 1200 360 6500 1425 1600 2420 100 250
NOTE: Average power dissipation of transients not to exceed 0.25W, 0.4W, 0.6W or 1W for model sizes 7mm, 10mm, 14mm and 20mm, respectively.
P
ART
NUMBER
MODEL
SIZE
DISC
D
IA.
(mm)
DEVICE
MODEL
N
UMBER
B
RAND-
ING
MAXIMUM RATING (85
o
C) SPECIFICATIONS (25
o
C)
CONTINUOUS TRANSIENT
VARISTOR VOLT-
AGE AT 1mA DC
TEST CURRENT
MAXIMUM
CLAMPING
VOLTAGE
8 x 20µs
TYPICAL
CAPACI-
TANCE
f = 1MHzV
RMS
V
DC
ENERGY
10 x 1000µs
PEAK
CURRENT
8 x 20µs
V
M(AC)
V
M(DC)
W
TM
I
TM
V
NOM
M
IN
V
NOM
M
AX V
C
I
PK
C
(V) (V) (J) (A) (V) (V) (A) (pF)
100
90
80
70
60
50
40
30
20
10
0
-55 50 60 70 80 90 100 110 120 130 140 150
AMBIENT TEMPERATURE (
o
C)
PERCENT OF RATED VALUE
FIGURE 1. CURRENT, ENERGY AND POWER DERATING
CURVE
FIGURE 2. PEAK PULSE CURRENT TEST WAVEFORM
100
90
50
10
O
1
T
T
1
T
2
TIME
PERCENT OF PEAK VALUE
O
1
= Virtual Origin of Wave
T = Time From 10% to 90% of Peak
T
1
= Virtual Front time = 1.25 • t
T
2
= Virtual Time to Half Value (Impulse Duration)
Example: For an 8/20µs Current Waveform:
8µs = T
1
= Virtual Front Time
20µs = T
2
= Virtual Time to Half Value
