A Topology of Class-AB OTA with Increased DC-‎Gain and Slew-Rate

محورهای موضوعی : Electrical Engineering

Shahrbanoo Ghorbanzadeh ¹ (Department of Electrical Engineering, Sari Branch, Islamic Azad University, Sari, Iran)
Hadi Dehbovid ² (Department of Electrical Engineering , Nour Branch, Islamic Azad University, Nour, Iran)
Alireza Ghorbani ³ (Department of Electrical Engineering, Sari Branch, Islamic Azad University, Sari, Iran)
Mehdi Abedi Pahnekola ⁴ (Department of Electrical Engineering, Sari Branch, Islamic Azad University, Sari, Iran)

تاریخ دریافت : 1400/03/03 تاریخ پذیرش : 1400/09/27 تاریخ انتشار : 1400/09/10

کلید واژه: Operational Trans- conductance Amplifier (OTA), Class- AB circuits, CMOS integrated circuits, Adaptive biasing,

چکیده مقاله :

The Operational Trans- conductance Amplifier (OTA)is a main building block in several analog signal and mixed- signal integrated circuits. This paper, a novel low power Class- AB CMOS Operational trans- conductance amplifier (OTA) with High gain and high slew rate is presented. The proposed two-stage OTA, the characteristics of class-AB are applied in both of the stages. The Use of active loads for the first stage provides the effective trans-conductance boosting and increased,DC-gain product. The nonlinear current mirrors boost the current of the second stage leading to the increase of the slew rate. The OTA canbe employed in low- voltage low- power circuits requiring a good performance/power tradeoff.Theoretical analysis and Cadence simulations prove the performance of the new OTA. The simulation results indicate that the DC gain is improved by abot 13db.The UGBW and phase margin of the proposed OTA are 305 MHZ and 65º ,respectively.

منابع و مأخذ:

[1] Francesco, C.,Pietro, M.,Gaetano, P.,Pasquale, T.,Alessandro, T.(2018). A Topology of Fully Differential Class-AB Symmetrical OTA With Improved CMRR. IEEE Transactions on Circuits and Systems II: Express Briefs, 65(11), 1504 – 1508.

[2] F, Centurelli., P, Monsurro., G, Parisi., P,Tommasino., A, Trifiletti. (2018). A 0.6 V class-AB rail-to-rail CMOS OTA exploiting threshold lowering. Electronics Letters, 54(15), 930-932.

[3] Torralba, A., Carvajal, R.G., Jimenez, M., et al.(2006).  Compact low-voltage class-AB analogue buffer. Electron. Lett, 42 (3), 152–154.

[4] Peluso, V., Vancorenland, P., Steyaert, M., et al. (1997).  900 mV differential class AB OTA for switched opamp applications, Electron. Lett,  33 (17), 1455–1456.

[5] Tomasz,  K. ,Fabian, K.(2020). A Compact 0.3-V Class AB Bulk-Driven OTA.. IEEE Transactions on Very Large Scale Integration (VLSI) Systems. 28 (1) ,224 – 232.

[6] Shirin, P. , Jaime, R. , Alejandro, R. , Manaswini, G. (2019) . Gain and Bandwidth Enhanced Class-AB OTAs.IEEE 62nd International Midwest Symposium on Circuits and Systems (MWSCAS) , 778- 781.

[7] Luis HC, F., Tales Cleber, P., Robson L, M. (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.

[8] George, R.,Spyridon, V. (2011). Low-voltage bulk-driven input stage with improved transconductance.International Journal of Circuit Theory and Applications, 39 (3) ,327-339.

[9] Luis HC, F., Sameer R, S. (2014). 60-dB gain OTA operating at 0.25-V power supply in 130-nm digital CMOS process.IEEE Transactions on Circuits and Systems I: Regular Papers, 61 (6) 1609-1617.

[10] Thandri, B. K.;Silva-Martinez, J.(2003). A robust feedforward compensation scheme for multistage operational trans-conductance amplifiers with no Miller Capacitors, IEEE Journal of Solid-State Circuits. 38 (2) 237-243.

[11] L. Callewaert, W. Sansen. (1990). Class AB CMOS amplifiers with high efficiency. IEEE Journal of Solid-State Circuits, 25 (3) 684–691.

[12] JA. Galan, AJ. López-Martín, RG. Carvajal, J. Ramírez-Angulo, C. Rubia-Marcos.(2007). Super class-AB OTAs with adaptive biasing and dynamic output current scaling. Circuits and Systems I: Regular Papers, 54(3)449-457.

[13] Lopez-Martin, A., Baswa, S., Ramirez-Angulo, J., Carvajal, R.G. (2005). Low-voltage super class AB CMOS OTA cells with very high slew rate and power efficiency. IEEE J. Solid-State Circuits. 40 (5) 1068–1077.

[14] Garde, M.P., Lopez-Martin, A., Carvajal, R.G., Ramirez-Angulo, J. (2018). Super class AB recycling folded cascode OTA. IEEE Journal of Solid-State Circuits, 53 (9) 2614 - 2623.

[15] Garde, M.P., Lopez-Martin, A., Ramirez-Angulo, J.( 2018). Power-efficient class AB telescopic cascode opamp. Electron. Lett, 54, (10) 620-622.

[16] Zuo, L., Islam, S.K. (2013). Low-voltage bulk-driven operational amplifier with improved transconductance, IEEE Trans. Cir. Syst. I, 60 (8) 2084-2091.

[17] Stepan Sutula, Michele Dei , LluísTerés, Francisco Serra-Graells, Variable-Mirror Amplifier: A New Family of Process-Independent Class-AB Single-Stage OTAs for Low-Power SC Circuits, IEEE Transactions on Circuits and Systems I: Regular Papers. 63 (2016) 1101-1110.

[18] Saso, J.M. Lopez-Martin, A., Garde, M.P., Ramirez-Angulo, J.(2017). Power-efficient class AB fully differential amplifier. Electron. Lett., 53 (19) 1298-1300.

[19] JEONGJIN, R. (2006). High-gain class-AB OTA with low quiescent current, Journal Analog Integr. Circuits Signal Process. 47,225–228.

[20] Sutula, S., Dei, M., Teres, L., and Serra-Graells, F.(2016). Variable-mirror amplifier: A new family of process-independent class-AB single-stage OTAs for low-power SC circuits. IEEE Trans. Cir. Syst. I , 63 (8) 1101-1110.

[21] Mohamad, Y.Tohid, M. (2014). A single-stage operational amplifier with enhanced transconductance and slew rate for switched-capacitor circuits.Journal. Analog Integr. Circuits Signal Process, 79(3)   589–598.

[22] Mohamad, Y.(2005). Hybrid cascode compensation for two-stage CMOS op-amps, IEICE transactions Electronics, 88 (22) 1161-1165.

[23] R.G. Carvajal, J. Ramirez-Angulo,  A. Torralba,  J.A.G. Galan,  A. Carlosena, F.M.  Chavero.The Flipped Voltage Follower: A Useful Cell for Low-Voltage Low-Power Circuit Design. IEEE Transactions on Circuits and Systems I: Regular Papers. 52 (7), 1276 – 1291.

[24] J. Guo, M. Ho, KY. Kwong, KN. Leung. (2015). Power-area-efficient transient-improved capacitor-free FVF-LDO with digital detecting technique. Electronics Letters, 51 (1),  94–96.

[25] M. J. M. Pelgrom, A. C. J. Duinmaijer, A. P. G. Welbers. (1989). Matching Properties of MOS Transistors. IEEE Journal Solid-State Circuits. 24 (5).