© 2013 Littelfuse, Inc.

43

Revised: May 8, 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.

Device Characteristics

At low current levels, the V-I curve of the multilayer

transient voltage suppressor approaches a linear (ohmic)

relationship and shows a temperature dependent effect.

At or below the maximum working voltage, the suppressor

maximum rated working voltage). Leakage currents at

maximum rated voltage are below 100μA, typically 25μA;

for 0402 size below 20μA, typically 5μA.

100%

1E-9

1E-8

SUPPRESSOR CURRENT (ADC)

10%

1E-7

1E-6

1E-5

1E-4

1E-3

1E-2

25

50

75

100

125oC

o

o

o

o

Clamping Voltage Over Temperature (V

100

10

20

V26MLA1206

40

60

80

100

120

140

V5.5MLA1206

0

-20

-40

-60

Typical Temperature Dependance of the Haracteristic

Curve in the Leakage Region

Speed of Response

The Multilayer Suppressor is a leadless device. Its

response time is not limited by the parasitic lead

inductances found in other surface mount packages.

The response time of the Z

than 1ns and the MLA can clamp very fast dV/dT events

such as ESD. Additionally, in "real world" applications,

the associated circuit wiring is often the greatest

factor effecting speed of response. Therefore, transient

suppressor placement within a circuit can be considered

important in certain instances.

GRAINS

DEPLETION

FIRED CERAMIC

DIELECTRIC

REGION

METAL

ELECTRODES

DEPLETION

REGION

METAL END

TERMINATION

Multilayer Internal Construction

Energy Absorption/Peak Current Capability

Energy dissipated within the MLA Series is calculated

by multiplying the clamping voltage, transient current

and transient duration. An important advantage of the

multilayer is its interdigitated electrode construction within

the mass of dielectric material. This results in excellent

current distribution and the peak temperature per energy

absorbed is very low. The matrix of semiconducting grains

combine to absorb and distribute transient energy (heat)

(see Speed of Response). This dramatically reduces peak

temperature; thermal stresses and enhances device

reliability.

As a measure of the device capability in energy and peak

current handling, the V26MLA1206A part was tested with

multiple pulses at its peak current rating (150A, 8/20μs). At

the end of the test,10,000 pulses later, the device voltage

characteristics are still well within specification.

100

10

0

V26MLA1206

2000

4000

6000

8000

10000

12000

NUMBER OF PULSES

PEAK CURRENT = 150A

8/20 s DURATION, 30s BETWEEN PULSES

Repetitive Pulse Capability

Figure 10

Figure 11

Figure 12

Figure 13