Method and apparatus to reduce footprint of ESD protection within an integrated circuit

摘要

An input/output (“I/O”) circuit has a first N-channel metal-oxide semiconductor (“NMOS”) field-effect transistor (“FET”) coupled to the input pin with a silicide block. A first P-channel metal-oxide semiconductor (“PMOS”) FET is directly connected to the input pin, with its N-well electrically coupled to an ESD well bias circuit. An NMOS low-voltage differential signal (“LVDS”) driver is also directly connected to the input pin, and has cascaded NMOS FETs. The first NMOS FET of the LVDS driver is fabricated within a first P-tap guard ring electrically coupled to ground and an N-well guard ring coupled to the ESD well bias. The second NMOS FET of the LVDS driver is fabricated within a second P-tap guard ring electrically coupled to ground.