Designing Ultra Low Voltage Low Power Active Analog Blocks for Filter Applications Utilizing the Body Terminal of MOSFET: A Review

The propelling demand for ultra-low voltage low power electronics has provided the much needed impetus to the research and design of analog building blocks working below 1 V supply. Numerous techniques are being adopted by the researchers to achieve ultra-low voltage low power operation and each vying to become the universal design choice. This study presents a survey of the two techniques namely the bulk driven technique and dynamic threshold technique that utilize the body terminal of the MOSFET to achieve the aforementioned objectives. A brief review of the principles of the two techniques, including a technical analysis of their applicability and limitations is presented. An inspection of extensively researched analogue active building blocks the operational transconductance amplifier and current conveyor designed using the body techniques is done. Various performance parameters like the supply voltage requirement, power dissipation, frequency response and dynamic range are discussed. The spectrum of applications that can be realised by these active blocks are also highlighted. In this study, operational transconductance amplifier and current conveyor active blocks will be designed utilizing the body techniques for tunable filter applications. The designed blocks are expected to work in between 0.4-0.8 V power supply dissipating 10 nW to 100 W of power. The expected frequency response is in the range of 100-500 kHz for low frequency applications and frequency response in the range of 4-200 MHz for high frequency applications. The designed blocks will be suitable for integration with biomedical devices and communication systems.