1V Square-Root Domain Low-Pass Filter using Translinear Loop Technology in Biomedical Engineering

A low voltage square root domain filter based on the MOSFET square law is proposed in this report. Through the verification of HSPICE simulation, the extendibility and the reliability of the design procedure are proved. Furthermore, the voltage supply is successfully leveled down to 1V by the level shifter 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 ability. The proposed circuit has been fabricated with TSMC 0.35 μm CMOS technology. The experimental results have verified the center frequency f3dB of the low-pass filter can be electronically tunable in the range of 0.4 MHz to 2.9 MHz. The total harmonic distortion (THD) is less than 0.7% for signal amplitude of 100 mV, and the power dissipation is less than 1.05 mW. (Life Science Journal. 2009; 6(4): 92-96) (ISSN: 1097 - 8135)

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