2

HB34 Varistor Series

Varistor Products

High Energy Industrial

87

www .littelfuse .com

Power Dissipation Ratings

Should transients occur in rapid succession, the average power

dissipation result is simply 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 must be derated as shown

in Figure 1.

Transient V-I Characteristics Curves

FIGURE 2. PEAK PULSE CURRENT TEST WAVEFORM

100

90

50

10

T

TIME

T = Time From 10% to 90% of Peak

Example: For an 8/20

µs Current Waveform:

8

20

FIGURE 3. CLAMPING VOLTAGE FOR V131HB34 - V751HB34

10000

1000

100

CURRENT (A)

V751HB34

V131HB34

V321HB34

V511HB34

V481HB34

V571HB34

V661HB34

TA = -55

oC TO 85oC

MAXIMUM CLAMPINGVOLTAGE

VARISTOR SIZE 34mm

130 TO 750 VM(AC) RATING

V271HB34

V251HB34

V151HB34

V421HB34

-5

-4

1E-3

0.01

0.1

1

10

100

1,000

10,000

100,000

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