2×VDD-Tolerant Crystal Oscillator Circuit Realized With 1×VDD CMOS Devices Without Gate-Oxide Reliability Issue

摘要

A new 2×VDD-tolerant crystal oscillator circuit realized with 1×VDD CMOS devices without suffering gate-oxide reliability issue is proposed, which is one of the key mixed-voltage I/O cells in a cell library. The proposed circuit is realized with only thin gate-oxide devices with floating n-well technique. The proposed 2×VDD-tolerant crystal oscillator circuit has been designed and verified in a 90-nm 1-V CMOS process to serve 1/2-V mixed-voltage interface applications.