An $8^{th}$-order Butterworth filter employing source follower based bi-quad sections capable of realizing high-Q pole pairs
- Resource Type
- Conference
- Authors
- Kalidasan, Sakthidasan; Walker, Ross
- Source
- 2022 29th IEEE International Conference on Electronics, Circuits and Systems (ICECS) Electronics, Circuits and Systems (ICECS), 2022 29th IEEE International Conference on. :1-4 Oct, 2022
- Subject
- Bioengineering
Components, Circuits, Devices and Systems
Computing and Processing
General Topics for Engineers
Geoscience
Robotics and Control Systems
Signal Processing and Analysis
Baseband
Bandwidth
Dynamic range
Energy efficiency
Tuning
Electronic circuits
- Language
Cross-coupled source follower (CCSF) structures have become compelling for continuous time baseband filter design and have typically been demonstrated with lower order Butterworth responses. The main advantages are simplicity and power efficiency since only two current branches are needed for a biquadratic section. While it has been shown to be efficient in realizing filters that demand only low-Q pole pairs (Q < 2), the conventional structure cannot be readily used to create high-Q poles, which are necessary in designing higher order filters with sharper transition bands. In this paper, we propose a modified CCSF filter with bulk tuning in RFSOI 45nm technology to generate high-Q pole pairs needed for higher order filters. We demonstrate the usefulness of the proposed modification by reporting the performance of an ${8}^{th}$ -order Butterworth filter. The results show that higher order filters can be effectively implemented with the modified CCSF circuit without significantly reducing the figure of merit. The $8^{th}$ -order filter consumes 4.04 m W for 20 MHz bandwidth while achieving a dynamic range of 69.1 dB for 830 mVpp signals.