ESDAxxL

3/6

The ESDA family has been designed to clamp fast

spikes like ESD. Generally the PCB designers

This is why we give the dynamic resistance in

addition to the classical parameters. The voltage

across the protection cell can be calculated with

the following formula:

Where Ipp is the peak current through the ESDA cell.

DYNAMIC RESISTANCE MEASUREMENT

The short duration of the ESD has led us to prefer

a more adapted test wave, as below defined, to the

classical 8/20

µs and 10/1000µs surges.

2.5

µs duration measurement wave.

As the value of the dynamic resistance remains

stable for a surge duration lower than 20

µs, the

2.5

µs rectangular surge is well adapted. In

addition both rise and fall times are optimized to

avoid any parasitic phenomenon during the

measurement of Rd.

CALCULATION OF THE CLAMPING VOLTAGE

USE OF THE DYNAMIC RESISTANCE

2µs

tp = 2.5µs

t

I

Ipp