CM1235

Rev. 3 | Page 2 of 14 | www.onsemi.com

Block Diagram

test run. The part is then subjected to standard production test to verify that all of the tested parameters are within spec after the 1000 strikes.

PicoGuard XS ESD Protection Architecture

Conceptually, an ESD protection device performs the following actions upon an ESD strike discharge into a

1.

When an ESD potential is applied to the system under test (contact or air-discharge), Kirchoff’s Current Law

(KCL) dictates that the Electrical Overstress (EOS) currents will immediately divide throughout the circuit,

based on the dynamic impedance of each path.

2.

Ideally, the classic shunt ESD clamp will switch within 1ns to a low-impedance path and return the majority of

the EOS current to the chassis shield/reference ground. In actuality, if the ESD component's response time

(t

cantly lower than the ASIC's I/O cell circuitry, then the ASIC will have to absorb a large amount of the EOS

energy, and be more likely to fail.

3.

Subsequent to the ESD/EOS event, both devices must immediately return to their original specifications, and

be ready for an additional strike. Any deterioration in parasitics or clamping capability should be considered a

failure, since it can then affect signal integrity or subsequent protection capability. (This is known as "multi-

strike" capability.)