Littelfuse MLA Varistor Series - Manual (Page 3)

© 2013 Littelfuse, Inc. 41
Revised: December 16, 2013
Varistor Products
MLA Varistor Series
Surface Mount Multilayer Varistors (MLVs) > MLA Series
Specifications are subject to change without notice.
Please refer to www.littelfuse.com/series/ML.html or MLA.html for current information.
MLA S
eries
Peak Current and Energy Derating Curve
When 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. For applications exceeding 125°C ambient
temperature, the peak surge current and energy ratings
must be derated as shown below.
100
80
60
40
20
0
-55 50 60 70 80 90 100 110 120 130 140 150
PERCENT OF
RA
TED
VALUE
AMBIENT TEMPERATURE ( o C)
FIGURE 1. PEAK CURRENT AND ENERGY
DERATING CURVE
T
1
T 2
100
50
0
O 1 TIME
PERCENT OF PEAK
VALUE
O 1 = VIRTUAL ORIGIN OF WAVE
t 1 = VIRTUAL FRONT TIME = 1.25 x t
(IMPULSE DURATION)
t = TIME FROM 10% TO 90% OF PEAK
t 2 = VIRTUAL TIME TO HALF VALUE
EXAMPLE:
FOR AN 8/20 s CURRENT WAVEFORM
8 s = t 1 = VIRTUAL FRONT TIME
20 s = t 2 = VIRTUAL TIME TO
HALF VALUE
FIGURE 2. PEAK PULSE CURRENT TEST WAVEFORM
FOR CLAMPING VOLTAGE
T
Peak Pulse Current Test Waveform for Clamping Voltage
Limit V-I Characteristic for V9MLA0402L Limit V-I Characteristic for V5.5MLA0402 to V18MLA0402
Limit V-I Characteristic for V3.5MLA0603 to V30MLA0603
1
10
100
1µA 10µA 100µA 1mA 10mA 1A 10A 100A
V9MLA0402L
V5.5MLA0402L Va
rist
or
Voltage (V)
MLA0402L Limit VI Curves
Current (A)
Limit V-I Characteristic for V3.5MLA0805L to V30MLA0805L
1
10
100
1000
10µA 100µA 1mA 10mA 100mA 1A 10A 100A
V5.5MLA0805L
V3.5MLA0805L
V9MLA0805L
V12MLA0805L
V14MLA0805L
V18MLA0805L
V26MLA0805L
V30MLA0805L
FIGURE 6. LIMIT V-I CHARACTERISTIC FOR V3.5MLA0805L TO V30MLA0805L
Va
rist
or
Voltage (V)
Current (A)
1
10
100
1000
10 µA 100 µA 1mA 10mA 100mA 1A 10A 100A
V30MLA0603
V26MLA0603
V18MLA0603
V14MLA0603
V9MLA0603, V9MLA0603L
V5.5MLA0603, V5.5MLA0603L
V3.5MLA0603
Va
rist
or
Voltage (V)
Current (A)
FIGURE 5. LIMIT V-I CHARACTERISTIC FOR V3.5MLA0603 TO V30MLA0603
1
10
100
1µA 10µA 100µA 1mA 10mA 1A 10A 100A
Current (A)
V18MLA0402
V14MLA0402
V9MLA0402
V5.5MLA0402
Va
rist
or
Voltage (V)
MLA0402 Limit VI Curves
0
1
= Virtual Origin of Wave
T = Time from 10% to 90% of Peak
T
1
= Rise Time = 1.25 x T
T
2
= Decay Time
Example - For an 8/20 µs Current Waveform:
8µs = T
1
= Rise Time
20µs = T
2
= Decay Time
Figure 1
Figure 2
Figure 3 Figure 4
Figure 5 Figure 6