Characterization and Modeling of Commercial ICs for System-Efficient ESD Design

Optimizing electrostatic discharge (ESD) protection strategies requires simulation models of both
on
- and
off
-die ESD devices, but detailed information about
on
-die ESD protection is rarely available. Methods are proposed in the following paper to characterize and model the
on
-chip ESD protection using only measurements, with minimal
a priori
information about how the protection is implemented. The characterization targets a three-terminal (rather than the traditional two-terminal) protection structure, including the I/O, Vdd, Vss pins, and allows for current to flow between multiple pins simultaneously. A previously-developed behavioral model for TVS devices is used to capture the ESD behavior of the integrated circuit (IC), including its linear, quasi-static, and transient nonlinear response. The approach is used to model the equivalent current that flows through the
on
-chip ESD protection of two commercial ICs. The model of the
on
-chip ESD protection is combined with a behavioral model of an
off
-chip transient voltage suppressor to demonstrate their combined performance in a system-efficient ESD design (SEED) simulation. The model is validated both when the IC is powered-
off
and powered-
on
. The SEED model was able to predict quasistatic and peak voltages and currents at the IC with less than a 10% error.