National Chiao-Tung University

Department of Electronics Engineering & Institute of Electronics

Dynamic Body-Biasing and Power-Gating Techniques for Low Power Design

Student : Tung-Shuan Cheng

Advisor : Dr. Wei Hwang


The low-power circuit designs using dynamic body-biasing and power-gating techniques are realized in this thesis. For the flexibility and reusability in System-on-Chip designs, an on-chip configurable body-bias generator that produces various voltage levels is proposed and simulated in TSMC 100nm technology. The output voltage can be controlled through digital input signals. A dual-level on-chip body-bias generator is presented and combined with SRAM cell arrays to observe the effectiveness in leakage suppression. Simulation results in TSMC 0.13um technology show that 75% and 64% net cell leakage reductions are achieved for 64-bit and 32-bit wordlines, respectively. The physical layout is implemented in TSMC 0.13um technology and triple-well structure is necessary for separating body nodes of transistors.

A column/row co-controlled SRAM cell arrays scheme is also proposed and simulations and layout are implemented in TSMC 0.13um technology. The cells on the same wordline are divided into blocks and each block has a dedicated gating device. The gating devices are controlled by signals from both column and row decoders. Simulation results show a great amount of active and standby power saving and power-delay product demonstrates that the induced performance overhead is insignificant. Moreover, the area overheads for 8-bit block and 16-bit block conditions are 20.7% and 12.1%, respectively, and only 8.1% is for 32-bit block condition. This technique can be applied to SRAM, register file, CAM, DRAM, flash memory, cache, or other similar memory and logic circuits.