Low-voltage high-gain large-capacitive-load amplifiers in 90-nm CMOS technology

Mojarad, Mortaza; Kamarei, Mahmoud

doi:10.1016/j.aeue.2014.12.005

Cited by 6 publications

(2 citation statements)

References 24 publications

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“…In this case, and according to [27], the criteria is that the higher the value of the FoM, the better the performance of the OTA. As the GBW is the objective function, the small-signal FoM s [5,40,41], is evaluated by (8), and the large-signal FoM l by (9).…”

Section: Feasible Sized Solutions Provided By Pso and Molmentioning

confidence: 99%

Sizing CMOS Amplifiers by PSO and MOL to Improve DC Operating Point Conditions

2020

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The sizes of the metal-oxide-semiconductor (MOS) transistors in an operational amplifier must guarantee strong direct current operating point (DCOP) conditions. This paper shows the usefulness of two population-based optimization algorithms to size transistors, namely—particle swarm optimization (PSO) and many optimizing liaisons (MOL). Both optimization algorithms link the circuit simulator SPICE to measure electrical characteristics. However, SPICE provides an output-file indicating that a transistor is in strong inversion but the DCOP can be in the limit, and it can switch to a different condition. In this manner, we highlight the application of PSO and MOL to size operational transconductance amplifiers (OTAs), which DCOP conditions are improved by the introduction of a procedure that handles constraints to ensure that the transistors are in the appropriate DCOP. The Miller and RFC-OTA are the cases of study, and their sizing is performed using UMC 180 nm CMOS technology. In both OTAs, the objective function is the maximization of the gain-bandwidth product under the main constraint of guaranteeing DCOPs to improve two figures of merit and to provide robustness to Monte Carlo simulations and PVT variations.

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Section: Feasible Sized Solutions Provided By Pso and Molmentioning

confidence: 99%

Sizing CMOS Amplifiers by PSO and MOL to Improve DC Operating Point Conditions

2020

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“…Operational transconductance amplifiers (OTAs) are widely used in capacitive sensor interface and switched capacitor circuits [1][2][3][4][5]. Enhancement of gain-bandwidth product (GBW), slew rate (SR) and current efficiency (CE) of OTA is required in application areas for large capacitive load, expeditious and accurate signal transition, and small power consumption.…”

Section: Introductionmentioning

confidence: 99%

A Complementary Recycling Operational Transconductance Amplifier with Data-Driven Enhancement of Transconductance

Li¹,

Hou²,

Ju³

et al. 2019

Electronics

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An improved operational transconductance amplifier (OTA) is presented in this work. The fully differential OTA adopts the current recycling technique and complementary NMOS and PMOS input branches to enhance the total transconductance. Moreover, in order to achieve higher current efficiency, a data-driven biasing circuit was developed to dynamically adjust the power consumption of the amplifier. Two comparators were added to detect the voltage difference at the input nodes, and when the differential input is large enough to activate either comparator, extra biasing current is activated and poured into the amplifier to enhance its slew rate and gain-bandwidth product (GBW). The threshold voltage of the complementary recycling folded cascode (CRFC)-based comparator is configured to suppress overshoot. Complementary common-mode feedback (CMFB) topology with local CMFB structure is built to acquire high common-mode gain. The OTA was fabricated in SMIC 0.18-µm CMOS technology. The experimental result based on a capacitive feedback loop shows that the data-driven operation improves the average slew rate of the amplifier from 10.2 V/µs to 55.5 V/µs while the power only increases by 150%. The OTA has good potential to satisfy the fast settling demands for capacitive sensing circuits.

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