National Chiao-Tung University

Department of Electronics Engineering & Institute of Electronics

A Reliable Dual Supply Single Gate Oxide I/O Driver with High Voltage Tolerant Input Feature Built in a 1.95nm Tox, 65nm CMOS Technology

Student : Hsiu-Wen Lin

Advisor : Dr. Wei Hwang


In this thesis, the new dual supply I/O buffer that uses only 1xVDD device to drive 2xVDD voltage and capable of tolerant 3xVDD input voltage is presented. Major challenges, e.g., gate oxide overstress issue, static current and circuit performance are overcome to achieve a reliable low power and high speed I/O driver design. Three new circuit blocks of output stage including dynamic bias circuit, gate tracking circuit and floating N-well tracking circuit are proposed for troubleshooting. Input stage with configured input threshold at half I/O power voltage is proposed and it shares the same dynamic bias circuit with output stage. The single gate oxide (SGO) I/O driver is verified successfully by N65LP spice model and consumes nano-ampere scale static current at all operation modes. The operation speed is up to 500MHz at transmitting modes and 300MHz at receiving modes with 30pF loading in port ¡§PAD¡¨ and 0.1pF in port ¡§C¡¨ in worst case condition.