A new gate-level body biasing technique for PMOS transistors in subthreshold CMOS circuits

Subthreshold operation enables CMOS circuits to operate using very low supply voltages and to dissipate extremely low power with moderate performance. The dynamic threshold MOS technique (DTMOS) is an effective way to improve subthreshold circuit performance. In this paper, we propose a new body biasing technique for PMOS transistors working in the subthreshold region. In the proposed PMOS body biasing technique, the n-wells of PMOS transistors are biased with the gate output. The new technique improves circuit performance over DTPMOS and consumes less power. Simulations done using 0.18 /spl mu/m CMOS technology show that the proposed technique improves a 3-input AND gate speed by 40.1% and has a 82.3% energy-delay-product (EDP) savings over the DTPMOS scheme at 0.37 V supply voltage and 2 MHz operating frequency.

[1]  Kaushik Roy,et al.  Low voltage low power CMOS design techniques for deep submicron ICs , 2000, VLSI Design 2000. Wireless and Digital Imaging in the Millennium. Proceedings of 13th International Conference on VLSI Design.

[2]  Fari Assaderaghi DTMOS: its derivatives and variations, and their potential applications , 2000, ICM 2000. Proceedings of the 12th International Conference on Microelectronics. (IEEE Cat. No.00EX453).

[3]  Jeffrey Bokor,et al.  Dynamic threshold-voltage MOSFET (DTMOS) for ultra-low voltage VLSI , 1997 .

[4]  Magdy A. Bayoumi,et al.  B-DTNMOS: a novel bulk dynamic threshold NMOS scheme , 2004, 2004 IEEE International Symposium on Circuits and Systems (IEEE Cat. No.04CH37512).

[5]  Kaushik Roy,et al.  Robust subthreshold logic for ultra-low power operation , 2001, IEEE Trans. Very Large Scale Integr. Syst..

[6]  M. Bayoumi,et al.  A novel ultra-low-energy bulk dynamic threshold PMOS scheme , 2003, 2003 46th Midwest Symposium on Circuits and Systems.

[7]  Manoj Sachdev,et al.  A sub-0.5 V dynamic threshold PMOS (DTPMOS) scheme for bulk CMOS technologies , 2001, ICM 2001 Proceedings. The 13th International Conference on Microelectronics..