Patent ID: 6433585
Filing Date: 2002-08-13
Classification: H03K

Abstract:
An input buffer with programmable input threshold comprising:a first buffer coupled to an I/O pad comprising a first buffer pull-up thick oxide device and a first buffer pull-down thick oxide device; a first pull-up device programmably coupled to be in parallel with the first buffer pull-up thick oxide device; a second pull-up device coupled between the first pull-up device and a first supply voltage and having a control electrode coupled to a first programmable cell; a first pull-down device programmably coupled to be in parallel with the first buffer pull-down thick oxide device; and a second pull-down device coupled between the first pull-down device and a ground supply and having a control electrode coupled to a second programmable cell, wherein the first buffer pull-up thick oxide device has a gate oxide thickness that is about twice the gate oxide thickness of the second pull-up device.