A very high-frequency CMOS complementary folded cascode amplifier

A wide-band, fast settling CMOS complementary folded cascode (CFC) transconductance amplifier for use in analog VLSI high frequency signal processing applications is introduced. The superior performance of the CFC architecture over that of the folder cascode (FC) or mirrored cascode (MC) approaches for VLSI amplifiers is demonstrated. The symmetrically configured complementary input stage provides a wide common-mode input voltage range. The amplifier performs as an operational transconductance amplifier (OTA) and displays a first-order dominant pole when loaded by a shunt capacitor. The transconductance amplifier is small in area (0.016 mm/sup 2/), and well suited for high frequency analog signal processing applications. Simulation and experimental results demonstrate a DC gain of approximately 50 dB, with a 0.1% settling response of under 10 ns for loads varied from 0 to 2 pF.<
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