Silicon Laboratories Inc.
System and method of high speed, high voltage swing electrostatic discharge protection

Abstract:

An ESD protection circuit for an IC having multiple diodes coupled in series between a signal pad and a reference pad including a first diode coupled to the signal pad, a last diode coupled to the reference pad, and at least one intermediate diode. The protection circuit includes a bias network which may include one or more resistors, each coupled in parallel with a corresponding intermediate diode. One or more capacitors may be included, each coupled in parallel with a corresponding intermediate diode. For diode strings with four or more diodes, the resistances of the resistors may increase in the direction from the signal pad to the reference pad. The capacitances of the capacitors, if included, may decrease in the direction from the signal pad to the reference pad. The reference pad may be a voltage supply pad, such as a ground pad or a positive supply voltage pad.