Bessel‐like compensation of three‐stage operational transconductance amplifiers

Abstract

In this paper, we introduce a simple and well-defined approach for the design of fast settling amplifiers suitable for switched-capacitor circuits and characterized by low capacitive loads, in the order of few pico-farad. In the specific, the design is based on a new Bessel-like compensation that sets the phase of the closed-loop amplifier to be linearly related to the frequency, thus emulating the behavior of an ideal delay, like in a Bessel filter. The proposed Bessel-like approach is validated through the design and the simulation of two 3-stage amplifiers in a 65-nm CMOS process. KEYWORDS feedback amplifiers, frequency compensation, operational transconductance amplifier, robust design, settling time | ln( )| GBW ,which, for a given settling error, , represents the settling time of the amplifier under test, t s , normalized by the settling time of an ideal single-pole amplifier with the same GBW. 28 By inspection of Table 1, it is apparent that the NST of the Int J Circ Theor Appl. 2018;46:729-747. wileyonlinelibrary.com/journal/cta

Design of Three-Stage OTAs from Settling-Time and Slew-Rate Constraints

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Efficient Design Strategy for Optimizing the Settling Time in Three-Stage Amplifiers Including Small- and Large-Signal Behavior

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A gm/ID-Based Design Strategy for IoT and Ultra-Low-Power OTAs with Fast-Settling and Large Capacitive Loads

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