Single Stage OTA biased by Voltage-Combiners with Enhanced Performance using Current Starving
Póvoa , R. P.
Martins, R. M.
; Goes, JG
IEEE Transactions on Circuits and Systems II: Express Briefs Vol. 1, Nº 1, pp. 1 - 5, November, 2017.
ISSN (print): 1558-3791
ISSN (online): 1549-7747
Journal Impact Factor: 1,136 (in 2015)
Digital Object Identifier: 10.1109/TCSII.2017.2777533
This brief presents an improved single-stage amplifier biased by voltage-combiners, through the proper usage of current starving. The topology designed and fabricated shows an enhancement of the low-frequency gain, an improvement in the establishing time due to enhanced gain-bandwidth product, and a high improvement of the energy efficiency. The circuit was optimized using AIDA-C, a state-of-the-art multi-objective multi-constraint analog IC sizing and optimization tool, and simulation results demonstrate that a gain above 60 dB and a figure-of-merit over 900 MHz×pF/mA are acquirable with this circuit, using the UMC 130-nm technology design kit. The circuit was fabricated and experimentally measured, presenting a gain of 58 dB with a figure-of-merit of 1102 MHz×pF/mA, for a 3.3 V supply source.