Self-adjusting threshold-voltage scheme (SATS) for low-voltage high-speed operation

A circuit technique to reduce threshold voltage fluctuation by a use of self-substrate-bias is introduced. The substrate bias is controlled so that leakage current of a representative MOSFET is adjusted constant with a feedback loop. The threshold voltage can be controlled within /spl plusmn/0.05 V and the speed gains under 1.5 V and 1V V/sub DD/ are estimated to be a factor of 1.3 and 3, respectively. A test chip is fabricated and effectiveness of the scheme is investigated.<<ETX>>