This paper presents the designing of a low voltage low power single ended operational transconductance amplifier (OTA) for low frequency application. The designed OTA combines three different schemes i.e. current splitting, current cancellation and source degeneration technique. Source degeneration method using resistor is one of the most simple and ubiquitous technique to linearize the transfer characteristics of OTA. Current splitting technique is utilized to reduce the transconductance of OTA and to improve the linearity. Current cancellation technique is used to further reduce the transconductance. The OTA circuit is operated in sub-threshold region due to the stringent power limitation requirement in integrated circuits. The transconductance of the OTA is 4.5 nA/V with a linear range of +/− 0.25 V. To test the applicability of the proposed OTA, a fifth order Butterworth OTA-C low pass filter is realized. The circuit is operated at a supply voltage of +/− 0.5 V and the power consumption of the filter is 487 nW. The DC gain of the filter is − 6.1 dB with a cutoff frequency of 250 Hz. THD of − 50.61 dB of the OTA-C filter is obtained for a 100 mVpp signal with 100 Hz frequency. The circuit shows the best THD performance with less pass band attenuation for single ended filter circuit. The circuit is simulated in cadence environment using 150 nm CMOS process technology.
This is a preview of subscription content, log in to check access.
Buy single article
Instant access to the full article PDF.
Price includes VAT for USA
Subscribe to journal
Immediate online access to all issues from 2019. Subscription will auto renew annually.
This is the net price. Taxes to be calculated in checkout.
Jihai, D., Weilin, X., & Baolin, W. (2015). An OTA-C filter for ECG acquisition systems with highly linear range and less pass-band attenuation. Journal of Semiconductor, 36(5), 055006-1–055006-6.
Kongpoon, M. (2013). A novel OTA-based voltage attenuation technique for very low frequency filtering using low-gm OTA filters. In International symposium on intelligent signal processing and communication systems, 12–15 November, https://doi.org/10.1109/ispacs.2013.6704635.
Mahmoud, S. A., Bamakharamah, A., & Al-Tunaji, S. A. (2013). Low noise low-pass filter for ECG detection system with digitally programmable range. Circuits, Systems and Signal Processing, 32(5), 2029–2045.
Lewinski, A., & Silva-Martinez, J. (2004). OTA linearity enhancement technique for high frequency applications with IM3 below − 65 dB. IEEE Transactions on Circuits and Systems II: Express Briefs, 51(10), 542–548.
Rasekh, A., & Bakhtiar, M. S. (2018). Design of low-power low area tunable active RC filters. IEEE Transaction on Circuits and Systems-II, 65(1), 6–10.
Grasso, A. D., Palumb, G., & Pennisi, S. (2015). High performance four- stage CMOS OTA suitable for large capacitive loads. IEEE Transaction on Circuits and Systems, 6(10), 2476–2484.
Akbari, M., & Hashemipour, O. (2016). A 63 dB gain OTA operating in subthreshold region with 20 nW power consumption. International Journal of Circuit Theory and Application, 45(6), 843–850.
Abdulaziz, M., Tormanen, M., & Sjoland, H. (2014). A compensation technique for two stage OTAs’. IEEE Transaction on Circuits and Systems-II, 61(8), 594–598.
Sokmen, O. G., Ercan, H., Tekin, S. A., & Alci, M. (2015). A novel low voltage low power OTA based on level shifter current mirror. Elektronika ir Elektrotechnika, 21(2), 39–43.
Grasso, A. D., Marano, D., Palumbo, G., & Pennisi, S. (2015). Design methodology of subthreshold three stage CMOS OTAs suitable for ultra-low-power low- area and high driving capability. IEEE Transactions on Circuits and Systems-I, 62(6), 1453–1462.
Mathad, R. S. (2014). Low frequency filter design using operational transconductance amplifier. IOSR Journal of Engineering (IOSRJEN), 04(4), 21–28.
Silva-Martinez, J., & Salcedo-Suñer, J. (1997). IC voltage to current transducers with very small transconductance. Analog Integrated Circuits and Signal Processing, 13(3), 285–293.
Mahmoud, S. A., Bamakharamah, A., & Al-Tunaji, S. A. (2014). Six order cascaded power line Notch filter for ECG Detection system with noise shaping. Circuits, Systems and Signal Processing, 33(8), 2385–2400.
Akbari, M., Nazari, M., Sharii, L., & Hashemipour, O. (2015). Improving power efficiency of two stage operational amplifier for biomedical applications. Analog Integrated Circuits and Signal Processing, 84(2), 173–183.
Cabrera-Bernal, E., Pennisi, S., Grasso, A. D., Torralba, A., & Carvajal, R. G. (2016). 0.7-V three-stage class-AB CMOS operational transconductance amplifier. IEEE Transactions on Circuits and Systems I, 63(11), 1807–1815.
Kuo, K. C., & Leuciuc, A. (2001). A linear MOS transconductor using source degeneration and adaptive biasing. IEEE Transactions on Circuits and Systems II: Analog and Digital Signal Processing, 48(10), 937–943.
Comer, D. J., & Comer, D. T. (2004). Operation of analog MOS circuits in the weak or moderate inversion region. IEEE Transactions on Education, 47(4), 430–435.
Ferreira, L. H. C., Pimenta, T. C., & Moreno, R. L. (2007). An ultra-low-voltage ultra-low-power CMOS miller OTA with rail-to-rail input/output swing. IEEE Transactions on Circuits and Systems—II: Express Briefs, 54(10), 843–847.
Chen, Y., Mak, P. I., D’Amico, S., Zhang, L., Qian, H., & Wang, Y. (2013). A single-branch third-order pole zero low-pass filter with 0.014-mm2 die size and 0.8-kHz (1.25-nW) to 0.94-GHz (3.99-mW) bandwidth-power scalability. IEEE transactions on circuits and systems II: Express briefs, 60(11), 761–765.
Sun, C.-Y., & Lee, S.-Y. (2017). A fifth order butterworth OTA-C LPF with multiple output differential input OTA for ECG applications. IEEE Transaction on Circuits & Systems-II: Express Brief, 65(4), 421–425.
Naik, S., Bale, S., Dessai, T. R., Kamat, G., &Vasantha, M. H. (2015). 0.5 V 225 nW, 100 Hz lowpass filter in 0.18 um CMOS process. In IEEE international advance computing conference (IACC) (pp. 165–169).
Sun, C.-Y., & Lee, S.-Y. (2009). Systematic design and modelling of OTA-C filter for poratable ECG detection. IEEE Transaction on Circuits & Systems-I, 3(1), 53–64.
Solis-Bustos, S., Silva-Martínez, J., Maloberti, F., & Sánchez-Sinencio, E. (2000). A 60 dB dynamic-range CMOS sixth-order 2.4 Hz lowpass filter for medical applications. IEEE Transactions on Circuits and Systems I, 47(12), 1391–1398.
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
About this article
Cite this article
Bano, S., Narejo, G.B. & Usman Ali Shah, S.M. Low Voltage Low Power Single Ended Operational Transconductance Amplifier for Low Frequency Applications. Wireless Pers Commun 106, 1875–1884 (2019). https://doi.org/10.1007/s11277-018-5726-1
- Low frequency
- Source degeneration
- Current splitting
- Operational transconductance amplifier