A switched-capacitor filter with dynamic switching bias OP amplifiers

Wakaumi, Hiroo

doi:10.1109/lascas.2017.7948046

Cited by 6 publications

(4 citation statements)

References 7 publications

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“…The voltage and current amplifier stages change the signal from continuous to discrete time and are therefore realized as switched capacitor (SC) circuits. SC amplifiers outperform continuous time amplifiers in low-power applications because they can be realized very efficiently with switched operational amplifiers (SOA) [18]. High on-chip resistances resulting in high noise and area contributions can be omitted.…”

Section: B Programmable Gain and Transimpedance Amplifiersmentioning

confidence: 99%

“…The bias currents are set to 100 nA, but not all seven currents are enabled at the same time in order to minimize the impact on overall AFE power consumption. Any unwanted shunt currents are avoided with the help of vectors N EN [2 : 0] (N enable) and P EN [2 : 0] (P enable), which control current switches [18]. They are connected to control signals M oh3-0 from CH-MUX and S/D-MUX and from the digital part.…”

Section: Reference Sourcesmentioning

confidence: 99%

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Flexible Multi-Channel Analog-Frontend for Ultra-Low Power Environmental Sensing

Jotschke

Reichel

Ossa

et al. 2021

IEEE Open J. Circuits Syst.

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The trend towards ubiquitous electronics drives the development of autonomous hardware components with longer operating times. This work presents a novel ultra-low power analog sensor frontend (AFE) for environmental sensing applications. Relevant operation parameters like resolution (6 to 13 bit), sample rate (1 to 7.5 kS/s), voltage gain (−6 to 12 dB), transimpedance (1.5 to 12 M ), and moving average (1 to 128 taps) are real-time programmable. Four input channels are separately configurable to process voltage, current and potentiometric signals of external or internal sources. The flexible channel-wise configuration enables processing of various signal types and therefore offers a versatile solution for sensors from the Internet-of-Things (IoT) market segment. The AFE integrates switched-capacitor amplifiers, 13 bit, 10 kS/s successive approximation analog-to-digital converter (SAR ADC), bias references, oscillator, digital signal pre-processing and communication in a system-on-chip. A novel sensor power regime supports the flexible read-out of commercial IoT sensors, resulting in excellent power consumption. Fabricated samples in 180 nm technology show an ultra-low power consumption of 8.8 µW. The SAR ADC achieves 10.6 effective bits while consuming 1.8 µW, resulting in a Figure-of-Merit of 116.0 fJ/conv.-step. Measurements with commercial sensors prove the AFE's suitability for an energy-harvester-powered IoT environmental sensor node.

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Section: B Programmable Gain and Transimpedance Amplifiersmentioning

confidence: 99%

Section: Reference Sourcesmentioning

confidence: 99%

Flexible Multi-Channel Analog-Frontend for Ultra-Low Power Environmental Sensing

Jotschke

Reichel

Ossa

et al. 2021

IEEE Open J. Circuits Syst.

View full text Add to dashboard Cite

show abstract

“…Further, the effect of OP Amp load capacitances on the frequency response is evaluated. This paper is an extension of work originally presented in LASCAS 2017 [11].…”

Section: Introductionmentioning

confidence: 97%

“…In this paper, a configuration of SC Butterworth low-pass filter (LPF) with DSBFC OP Amps [11] as an example of application of the DSBFC OP Amp is proposed, which enables low power consumption and is suitable for achieving wide bandwidths and operation in low power supply voltages, and its availability is also evaluated for the performance of frequency response and power dissipation. Further, the effect of OP Amp load capacitances on the frequency response is evaluated.…”

Section: Introductionmentioning

confidence: 99%