Low-Voltage Low-Pass and Band-Pass Elliptic Filters Based on Log-Domain Approach Suitable for Biosensors

This research proposes bipolar junction transistor (BJT)-based log-domain high-order elliptic ladder low-pass (LPF) and band-pass filters (BPF) using a lossless differentiator and lossless and lossy integrators. The log-domain lossless differentiator was realized by using seven BJTs and one grounded capacitor, the lossy integrator using five BJTs and one grounded capacitor, and the lossless integrator using seven BJTs and one grounded capacitor. The simplified signal flow graph (SFG) of the elliptic ladder LPF consisted of two lossy integrators, one lossless integrator, and one lossless differentiator, while that of the elliptic ladder BPF contained two lossy integrators, five lossless integrators, and one lossless differentiator. Log-domain cells were directly incorporated into the simplified SFGs. Simulations were carried out using PSpice with transistor array HFA3127. The proposed filters are operable in a low-voltage environment and are suitable for mobile equipment and further integration. The log-domain principle enables the frequency responses of the filters to be electronically tunable between 10k Hz–10 MHz. The proposed filters are applicable for low-frequency biosensors by reconfiguring certain capacitors. The filters can efficiently remove low-frequency noise and random noise in the electrocardiogram (ECG) signal.

[1]  Mehmet Sagbas,et al.  Electronically tunable current-mode second-order universal filter using minimum elements , 2004 .

[2]  M. J. Deen,et al.  A 10 MHz elliptic log-domain filter in a standard CMOS process , 2002, 2002 IEEE International Symposium on Circuits and Systems. Proceedings (Cat. No.02CH37353).

[3]  F. Montecchi.  Time-shared switched-capacitor ladder filters insensitive to parasitic effects , 1984 .

[4]  Costas Psychalinos,et al.  On the exact realization of log-domain elliptic filters using the signal flow graph approach , 2003, IEEE Trans. Circuits Syst. II Express Briefs.

[5]  D. R. Frey,et al.  Log-domain filtering: An approach to current-mode fil-tering , 1993 .

[6]  P. Gray,et al.  Design techniques for MOS switched capacitor ladder filters , 1978 .

[7]  Pipat Prommee,et al.  High performance electronically tunable log-domain current-mode PID controller , 2017, Microelectron. J..

[8]  K. Dejhan,et al.  Single-input Multiple-output Tunable Log-domain Current-mode Universal Filter , 2013 .

[10]  Robert W. Adams,et al.  Filtering in the Log Domain , 1979 .

[11]  Oguzhan Cicekoglu,et al.  First-order allpass sections-based current-mode universal filter using ICCIIs , 2000 .

[12]  Roman Sotner,et al.  New Solution of a Frequency Filter with Reconnection-less Reconfiguration of Its Transfer , 2019, 2019 29th International Conference Radioelektronika (RADIOELEKTRONIKA).

[13]  Roman Sotner,et al.  Novel Design Solution of Reconnection-less Electronically Reconfigurable Filter , 2019, 2019 MIXDES - 26th International Conference "Mixed Design of Integrated Circuits and Systems".

[14]  Kobchai Dejhan,et al.  High-frequency log-domain current-mode multiphase sinusoidal oscillator , 2010, IET Circuits Devices Syst..

[15]  Neeta Pandey,et al.  LC-ladder filter systematic implementation by OTRA , 2016 .

[16]  Pipat Prommee,et al.  Electronically Tunable Current-mode High-order Ladder Low-pass Filters Based on CMOS Technology , 2015 .

[17]  Kobchai Dejhan,et al.  Log-domain multiphase sinusoidal oscillator , 2011, 2011 IEEE 54th International Midwest Symposium on Circuits and Systems (MWSCAS).

[18]  Pipat Prommee,et al.  Electronically tunable MOS-only current-mode high-order band-pass filters , 2017, Turkish J. Electr. Eng. Comput. Sci..

[19]  Yichuang Sun,et al.  Continuous-Time Active Filter Design , 1998 .

[20]  Pipat Prommee,et al.  Log-domain High-order Low-pass and Band-pass filters , 2017 .

[21]  Jan Jerabek,et al.  New Low-Voltage CMOS Differential Difference Amplifier (DDA) and an Application Example , 2018, 2018 IEEE 61st International Midwest Symposium on Circuits and Systems (MWSCAS).

[22]  I.A. Khan,et al.  First Order Current Mode Filters and Multiphase Sinusoidal Oscillators Using MOCCIIs , 2006, 2006 International Conference on Microelectronics.

[23]  CHUNYUAN FENG.  THE DESIGN OF OTA-C FILTER BASED ON THE PROTOTYPE OF LADDER LC FILTER , 2013 .