Overview on the prior designs of the mixed-voltage I/O buffers is provided in this work. A new 2.5/5-V mixed-voltage I/O buffer realized with only thin gate-oxide devices is proposed. The new proposed mixed-voltage I/O buffer with simpler dynamic n-well bias circuit and gate-tracking circuit can prevent the undesired leakage current paths and the gate-oxide reliability problem, which occur in the conventional CMOS I/O buffer. The new mixed-voltage I/O buffer has been fabricated and verified in a 0.25-μm CMOS process to serve 2.5/5-V I/O interface. Besides, another 2.5/5-V mixed-voltage I/O buffer without the subthreshold leakage problem for high-speed applications is also presented in this work. The speed, power consumption, area, and noise among these mixed-voltage I/O buffers are also compared and discussed. The new proposed mixed-voltage I/O buffers can be easily scaled toward 0.18- μm (or below) CMOS processes to serve other mixed-voltage I/O interfaces, such as 1.8/3.3-V interface.
|Number of pages||12|
|Journal||IEEE Transactions on Circuits and Systems I: Regular Papers|
|State||Published - 1 Sep 2006|
- Gate-oxide reliability
- Gate-tracking circuit
- Mixed-voltage I/O buffer