A 1.2-V pseudo-differential OTA with common-mode feedforward in 65-nm CMOS
2010 (English)In: 17th IEEE International Conference on Electronics, Circuits, and Systems., www.ieee.org , 2010, 29-32 p.Conference paper (Refereed)
In this work, we describe the implementation of a 1. 2-V pseudo-differential operational transconductance amplifier (OTA) with common-mode feedforward (CMFF) and inherent common-mode feedback (CMFB) in a 65-nm, digital CMOS process. The OTA architecture provides an inherent CMFB when cascaded OTA structures are utilized andthis work has studied a cascaded amplifier consisting of fourstages. Due to the low-gain using core 65-nm circuit devices, the overall gain must be distributed on all four stages to acquire a gain of more than 60 dB, while maintaining a-3-dB bandwidth of 200 MHz. To achieve high gain, we propose using a modified, positive-feedback, cross-coupled input differential stage. The modified OTA achieves a high output swing of ± 0.85 V due to only two stacked transistors, 88 dB DC gain and a third-order harmonic of -60 dB for 800 mVpp at 30 MHz. Further on, in a capacitive buffer configuration, we achieve a high slew rate of 1240 V/µS, -3-dB bandwidth of 509 MHz, signal-to-noise ratio of 63 dB while consuming 10.4 mW power.
Place, publisher, year, edition, pages
www.ieee.org , 2010. 29-32 p.
Operational transconductance amplifiers, differential amplifiers, feedforward amplifiers, CMOS analog integrated circuits.
Other Electrical Engineering, Electronic Engineering, Information Engineering
IdentifiersURN: urn:nbn:se:liu:diva-70358DOI: 10.1109/ICECS.2010.5724446OAI: oai:DiVA.org:liu-70358DiVA: diva2:438499