Low Voltage Tunable Square-Root Domain Band-Pass Filter with Translinear Loop Technique in Biomedical Engineering

A low voltage square root domain filter based on the MOSFET square law is proposed in this thesis. Through HSPICE simulation, the extendibility and the reliability of the design procedure are verified. Furthermore, the supply voltage is successfully reduced down to 0.9V by the Flipped Voltage Follower (FVF) low-voltage technique without regarding the performance of the filters. The proposed filter structure has the merits of low-power voltage supply operation, high frequency operation, and the wide range of pole frequency tuning capability. The proposed circuit has been simulation with the TSMC 0.18 μm CMOS technology. The experimental results have demonstrated that the center frequency f0 of the band-pass filter can be electronically tunable in 774-914kHz with tunable bias-current, 1.78% total harmonic distortion (THD), and the power dissipation is less than 387μW at a 0.9V supply voltage. [Life Science Journal. 2010; 7(1): 30 – 33] (ISSN: 1097 – 8135).