Kumaravel SUNDARAM, Sudheer Raja VENISHETTY

Modified recycling folded cascode OTA with enhancement in transconductance and output impedance

A modified recycling folded cascode (MRFC) operational transconductance amplifier (OTA) for achievinghigh DC gain, slew rate, and unity gain bandwidth (UGB) is proposed in this paper. Positive feedback is adopted toenhance DC gain and unity gain bandwidth. The proposed MRFC OTA is compared with conventional folded cascode(FC), recycling folded cascode (RFC), and other OTAs existing in the literature. Three OTAs, FC, RFC, and MRFC,are realized and implemented using the UMC 180 nm CMOS process for the same bias current of 300 µA. The designsare simulated in the Cadence Spectre Environment. From the simulation results, it may be noted that the proposedamplifier achieves a gain of 76.24 dB and unity gain bandwidth of 74.7 MHz with an input referred noise and slew rateof 139.2 µVrms and 64.05 V/µs respectively. The proposed amplifier occupies an area of 2760 µm2.

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