A versatile 3.3 V/2.5 V/1.8 V CMOS I/O driver built in a 0.2 /spl mu/m 3.5 nm Tox 1.8 V CMOS technology

The continued scaling of transistor performance is delivering unprecedented microprocessor performance. However, the logic supply voltage, Vdd, is being reduced at a faster rate than the required I/O voltage level, OVDD. OVDD scales more slowly due to peripherals, which are built on mature technologies that require higher OVDD. Time-to-market constraints and chip integration issues further impose a single I/O driver as the desired solution. The I/O driver must meet the reliability constraints of the 3.3 V interface with a transistor that has a 3.5 nm Tox (no dual-gate oxide processing step). The 128b L2 interface must run at 400MHz clock rate and the 128b system interface at 150MHz. Both interfaces are compatible with the 3.3V/2.5V interfaces ofthe PowerPC TM 750, yet support more aggressive 1.8V systems.