A class-AB linear transconductor with enhanced linearity

Bocciarelli, Cristian; Centurelli, Francesco; Monsurrò, Pietro; Spinogatti, Valerio; Trifiletti, Alessandro

doi:10.1016/j.aeue.2021.153955

Cited by 5 publications

(6 citation statements)

References 46 publications

(38 reference statements)

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“…35 Several CMOS OTA structures with improved linearity have been successfully employed in designing filters. 24,25,36 One of the best examples of THD improvement is the differential biasing technique based OTA reported by Sanchez et al 37 which improves linear range as well as dynamic range (DR) while maintaining common mode and transconductance. However, a trade-off needs to be established between THD and gain of OTA.…”

Section: Introductionmentioning

confidence: 99%

“…Besides this, the total harmonic distortion ( THD ) is an important parameter used to quantify the harmonics present in the voltage waveforms 35 . Several CMOS OTA structures with improved linearity have been successfully employed in designing filters 24,25,36 . One of the best examples of THD improvement is the differential biasing technique based OTA reported by Sanchez et al 37 which improves linear range as well as dynamic range ( DR ) while maintaining common mode and transconductance.…”

Section: Introductionmentioning

confidence: 99%

“…The low voltage operation of OTA can be established by using bulk‐driven 38 and bulk‐driven floating‐gate 39 MOSFETs in input stage as well by using self cascode MOSFETs as tail devices. The extensive literature survey executed for OTA establishes the fact that circuit designers still face challenge of accomplishing combination of high‐gain, high gain‐bandwidth ( GBW ), low THD , low IRN , low power, low settling time ( ST ) and low voltage operation 24,25,36,39,40 …”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Design of low‐voltage low‐noise operational transconductance amplifiers for low frequency applications

Sharma,

Kumar,

Madan

et al. 2024

Int J Numerical Modelling

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Low‐noise and low‐voltage operation is prime requirement of an operational transconductance amplifier for low frequency applications. However, achieving low‐noise operation at low supply voltages is a challenging task in CMOS technology owing to noise‐power and noise‐stability tradeoffs. This article outlines, the design of four differential bias self‐cascode (DBSC) operational transconductance amplifiers (OTAs) working at ±0.7 V. The four design techniques namely gate driven (GD), bulk driven (BD), bulk driven quasi‐floating gate (BDQFG), and gate driven quasi floating bulk (GDQFB) have been applied on DBSC OTAs. The designing aspects and performance parameters of these four OTAs such as gain, gain‐bandwidth, input referred noise (IRN), settling time (ST), common mode rejection ratio (CMRR), total harmonic distortion, input impedance, transconductance, power consumption, area consumption and process/mismatch variations have been fairly compared in this work. These DBSC OTAs have been designed and simulated using a standard 0.18‐μm 6M1P CMOS N‐well process. The results infer GD DBSC OTA shows high CMRR of 125.83 dB. While the BD DBSC OTA consumes very low power of 0.2 μW. The BDQFG DBSC OTA shows low 1% ST of 24.83 μS. The GDQFB DBSC OTA show high transconductance (2.35 mS), high gain (64.97 dB), and low IRN (0.40 μV/√Hz at 10 Hz). The theoretical predictions for these OTAs agree with the post‐layout simulations. The proposed OTAs can be used for designing various analog circuits such as programmable gain amplifiers, variable gain amplifiers, and transimpedance amplifiers for low‐frequency biomedical and health care applications.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Design of low‐voltage low‐noise operational transconductance amplifiers for low frequency applications

Sharma,

Kumar,

Madan

et al. 2024

Int J Numerical Modelling

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“…The idea of linearized transconductors with degenerated input pair and loop control is discussed in [32]. Several solutions based on transistor in the triode region [33], [34], or floating-gate [35], body-driven [36] and cross-coupled cells [37] have been also reported and combined with efficient techniques such as adaptive biasing [38]- [42], master-slave automatic tuning [43], and cancellation of the nonlinear terms [44], [45]. Most of the above methodologies, however, establish inevitable trade-offs between the power, area and noise parameters and the DR.…”

Section: Introductionmentioning

confidence: 99%

Ladder-Type G_m -C Filters With Improved Linearity

2023

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A simple yet effective approach to improve the linearity of the transconductor-capacitor (Gm−C) filters is proposed without any area or power overhead. Following a generalized nodal analysis, the transconductors of classical filter topology are rewired such that their input differential voltage lies within the linear regime. The effectiveness of the proposed method is validated through the design and simulation of a fifth-order Butterworth low-pass filter (LPF) in a standard 65-nm CMOS process. The proposed filter implementation occupies 0.0164 mm 2 (0.003 mm 2 /pole) die area and consumes 167-µW for the cut-off frequency of 1-MHz. Operating at 1-V voltage supply, it shows an in-band total harmonic distortion (THD) of −49.14 dB for 200-mV peak-to-peak 1MHz differential voltage. An in-band 3rd-order intercept point (IIP3) of 9.36 dBm is also achieved with an in-band spurious-free-dynamic range (SFDR) greater than 53-dB, all of which reflect meaningful improvements relative to the classical architecture and despite the modest linearity performance of the internal Gm stages.INDEX TERMS Analog filter, Butterworth approximation, complementary metal-oxide-semiconductor (CMOS), continuous-time, Gm−C, linearity, low-pass filter, low-power, operational transconductance amplifier (OTA), and signal flow graph (SFG).

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“…13,14 Adaptive bias methods have been presented to improve the accuracy and linearity of G m -C filters. 15,16 These methods are mainly based on adjusting the tail current source based on the amplitude of the input signal, which increases the accuracy and efficiency of these filters. However, the use of these methods often requires high power consumption and is not suitable for biomedical applications.…”

Section: Introductionmentioning

confidence: 99%

A low power‐area low pass G_m‐C filter in biomedical analog front end for biosignal acquisition

Vafaei,

Parhizgar,

Abiri

et al. 2023

Circuit Theory & Apps

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SummaryIn this paper, a low‐power transconductor‐capacitor (Gm‐C) filter with programmable cutoff frequency is designed for electroencephalogram (EEG), electrocardiogram (ECG), and surface electromyography (sEMG) biosignals. The second‐order Butterworth low pass filter (LPF) is designed as an interface between an instrumentation amplifier (IA) and an analog‐to‐digital converter (ADC). The proposed Gm‐C filter suppresses out‐of‐band components and also plays an anti‐aliasing role. With the variable transconductance based on flipped voltage follower (FVF), the cutoff frequencies of 100 Hz, 560 Hz, and 1.5 kHz are obtained for EEG, ECG, and sEMG, respectively. This structure is highly accurate by using a robust and low‐power common mode feedback (CMFB). With 0.8 V supply voltage, the total power consumption of the filter is only 56 nW, 100 nW, and 221 nW for cutoff frequencies of 100 Hz, 560 Hz, and 1.5 kHz, respectively. The proposed Gm‐C filter is simulated in TSMC 65 nm CMOS technology and occupies an area of 0.12 mm2. The figure of merit (FOM) of the proposed filter is equal to 1.9 pW/pole.

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A class-AB linear transconductor with enhanced linearity

Cited by 5 publications

References 46 publications

Design of low‐voltage low‐noise operational transconductance amplifiers for low frequency applications

Design of low‐voltage low‐noise operational transconductance amplifiers for low frequency applications

Ladder-Type G_m -C Filters With Improved Linearity

A low power‐area low pass G_m‐C filter in biomedical analog front end for biosignal acquisition

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A class-AB linear transconductor with enhanced linearity

Cited by 5 publications

References 46 publications

Design of low‐voltage low‐noise operational transconductance amplifiers for low frequency applications

Design of low‐voltage low‐noise operational transconductance amplifiers for low frequency applications

Ladder-Type Gm -C Filters With Improved Linearity

A low power‐area low pass Gm‐C filter in biomedical analog front end for biosignal acquisition

Contact Info

Product

Resources

About

Ladder-Type G_m -C Filters With Improved Linearity

A low power‐area low pass G_m‐C filter in biomedical analog front end for biosignal acquisition