Ultra-low-power bulk-driven fully differential subthreshold OTAs with partial positive feedback for Gm-C filters

Sharan, Tripurari; Chetri, Priyanka; Bhadauria, Vijaya

doi:10.1007/s10470-017-1065-5

Cited by 29 publications

(12 citation statements)

References 35 publications

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“…One choice is to use continuous time operational transconductance ampli er (OTA) and capacitor having very low transconductance (Gm) that can determine the very low cut-off frequency. Several research articles have discussed the use of OTA for designing low Gm and thus low cut-off frequency [10][11][12], but the issue of using OTA-C lter is that it requires extra linearization techniques to maintain the linearity of OTA, because the linearity of OTA is poor. Thus large numbers of transistors are required in designing of OTA-C lter.…”

Section: Original Papermentioning

confidence: 99%

7.2 nW 68 dB DR Fourth Order Self-compensated Low Pass Filter for Portable ECG Application

Bano

Narejo

Ali

2019

ABE

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This paper describes the designing of a fourth order low-pass lter (LPF) for portable ECG application. The proposed lter is designed by cascading one P-biquad and one N-biquad to form a fourth order lter. It is self-compensated and provides a 0 dB gain. It also acquires the same input and output common mode voltages, which helps to produce higher order lters. It consumes power of 7.2 nW with a supply voltage of 1.2 V. Dynamic range of 68.1 dB with noise of 61.2 µVrms is obtained. The proposed lter is designed for a cutoff frequency of 230 Hz, suitable for ECG application. With 100 Hz frequency and 100 mV pp ac amplitude, HD 3 of 71 dB is achieved. The circuit is simulated in cadence software using Silterra 130 nm CMOS technology. Compared with other state-of-the-art designs, this novel LPF provides the largest dynamic range and the best gure of merit (FOM).

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Section: Original Papermentioning

confidence: 99%

7.2 nW 68 dB DR Fourth Order Self-compensated Low Pass Filter for Portable ECG Application

Bano

Narejo

Ali

2019

ABE

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“…OTA is an important building block for analogue circuits [1][2][3][4] and widely used in low power applications such as biomedical signal processing [5,6]. OTA for biomedical analogue front-end determines the performance of the circuit, such as power consumption, supply voltage, noise, and linearity [1,[6][7][8][9].…”

Section: Introductionmentioning

confidence: 99%

“…If batteries are the power source, low energy consumption implicates more operation time; and for wireless supply, the low consumptions would allow greater operating distances. To decrease the supply voltage, bias current, and power, it is possible to bias the OTA transistors in the weak inversion region [4,5,[10][11][12][13].…”

Section: Introductionmentioning

confidence: 99%

“…An OTA with MOS transistors operating in the weak inversion region has a low transconductance, which is important to implement an integrated Gm-C filter with low capacitances and also, as a consequence, with less chip area [13][14][15], which is very important in biomedical acquisition systems [16]. The transistor drain current in weak inversion region depends exponentially on the input voltage, and as a result, the linear range is low [5,6,14,15,17]. The linear range is defined as the input differential voltage when the THD is at 1% [3,12,15,18], usually expressed in units of peak-to-peak (Vpp).…”

Section: Introductionmentioning

confidence: 99%

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Biasing technique to improve total harmonic distortion in an ultra‐low‐power operational transconductance amplifier

Sánchez

Moreno

Ferreira

et al. 2019

IET Circuits, Devices & Systems

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This study presents a new technique based on large signal analysis, to enhance the total harmonic-distortion (THD) in an ultra-low-power operational transconductance amplifier (OTA). The proposed technique is used to implement an ultra-lowpower gate-driven and bulk-driven OTA with high linear range. Mismatch and post-layout simulations in 0.13 μm CMOS technology demonstrate that the proposed technique can improve the THD and the dynamic range, without affecting the transconductance tuning and the common-mode control. It achieves a 183 and 640 mVpp linear ranges for gate-driven and bulk-driven OTA, and a 61.8 dB dynamic range at 0.5 V with 26.35 nW power dissipation.

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“…Since the increasing density of components allows for more electronic functions per unit area, the power per electronic function has to be lowered in order to prevent overheating of the chip; thus LV LP designs are necessary [6]. Different design techniques have been proposed in the literature to reduce the supply voltage as well as the power consumption [7][8][9], but the reduction in the threshold voltage (V th ) has not been reduced by the same amount. With a low supply voltage, the threshold voltage is the main limitation in designing of low voltage analog integrated circuits [10].…”

Section: Introductionmentioning

confidence: 99%

Power Efficient Fully Differential Bulk Driven OTA for Portable Biomedical Application

2018

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This paper presents a power efficient, bulk driven, source degenerated fully differential operational transconductance amplifier (OTA), operating in the subthreshold region. The input part of the OTA consists of a bulk driven source degenerated differential pair and cross coupled transistors to improve the linearity of OTA. It consists of a bulk driven pair to reduce the supply voltage and to improve the linearity. The proposed fully differential OTA has utilized self-cascode current mirror loads which increases the output impedance and hence the overall intrinsic gain. A subthreshold region is adopted to reduce the power consumption of the circuit. For a 200 mVpp sinusoidal input at 100 Hz, a total harmonic distortion (THD) of −58.56 dB is achieved. The gain, gain bandwidth (GBW), phase margin (PM) and gain margin (GM) values obtained were 48.4 dB, 3.1 KHz, 80 • and 19.01 dB, respectively. The common mode rejection ratio (CMRR), power supply rejection ratio (PSRR) and slew rate +/− values were 146.3 dB, 83 dB and 99.56/100 V/ms, respectively. The circuit is capable of operating under a supply voltage of 0.8 V with a power consumption of 59.04 nW, which proves that the circuit is suitable for portable biomedical devices. The proposed circuit is simulated in CADENCE environment virtuoso using LFoundry 150 nm Complementary metal oxide semiconductor (CMOS) process technology.

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Ultra-low-power bulk-driven fully differential subthreshold OTAs with partial positive feedback for Gm-C filters

Cited by 29 publications

References 35 publications

7.2 nW 68 dB DR Fourth Order Self-compensated Low Pass Filter for Portable ECG Application

7.2 nW 68 dB DR Fourth Order Self-compensated Low Pass Filter for Portable ECG Application

Biasing technique to improve total harmonic distortion in an ultra‐low‐power operational transconductance amplifier

Power Efficient Fully Differential Bulk Driven OTA for Portable Biomedical Application

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