Temperature De-rating

When transients occur in rapid succession, the average power dissipa-

tion 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

surge current and energy ratings must be derated as shown in Figure 1.

100

80

60

40

20

0

-55

50

60

70

80

90

100

110 120

130 140 150

FIGURE 1. PEAK CURRENT AND ENERGY

DERATING CURVE

100

50

0

TIME

(IMPULSE DURATION)

t = TIME FROM 10% TO 90% OF PEAK

EXAMPLE:

FOR AN 8/20

µs CURRENT WAVEFORM

8

20

HALFVALUE

FIGURE 2. PEAK PULSE CURRENT TEST WAVEFORM

FOR CLAMPING VOLTAGE

t

FIGURE 3. LIMIT V-I CHARACTERISTIC FOR V5.5MLA0402 TO V18MLA0402

100

10

1

µA

CURRENT (A)

MAXIMUM LEAKAGE

10

µA

100

µA

1mA

10mA

100mA

1A

10A

100A

MAXIMUM CLAMPING VOLTAGE

V18MLA0402

V14MLA0402

V09MLA0402

V5.5MLA0402

ML Varistor Series

Surface Mount Varistors

Multilayer Transient Voltage Surge Suppressors

143

www .littelfuse .com

3

Next

Previous