A 34-mV Startup Ring Oscillator Using Stacked Body Bias Inverters for Extremely Low-Voltage Thermoelectric Energy Harvesting

Nishi, Masaya; Matsumoto, Kaori; Kuroki, Nobutaka; Numa, Masahiro; Sebe, Hikaru; Matsuzuka, Ryo; Maida, Osamu; Kanemoto, Daisuke; Hirose, Takahisa

doi:10.1109/newcas49341.2020.9159838

Cited by 7 publications

(7 citation statements)

References 14 publications

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“…Energy harvesting and power management techniques have been developed towards battery-and maintenance-free autonomous IoT (Internet-of-Things) devices. [1][2][3][4][5][6][7][8][9][10][11][12][13] Intermittent power management systems, shown in Fig. 1, are widely used to operate application circuits and systems stably because the output voltages of small energy harvesters are usually low and easily lost.…”

Section: Introductionmentioning

confidence: 99%

Switched-capacitor voltage buck converter with variable step-down and switching frequency controllers for low-power and high-efficiency IoT devices

Matsuzuka

Kanzaki

Matsumoto

et al. 2023

Jpn. J. Appl. Phys.

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This paper proposes a switched-capacitor voltage buck converter (SC-VBC) with variable step-down controller (VSC) and switching frequency controller (SFC). The VSC and SFC change the step-down ratio and switching frequency of the SC-VBC in accordance with the input voltage and load current, respectively, enabling the converter to operate eﬃciently with a wide-ranging input voltage and load current. Measurements of a prototype chip demonstrated that our SC-VBC achieved a wide input voltage range and high eﬃciency of 1.3 – 2.6 V and 69%, respectively.

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Section: Introductionmentioning

confidence: 99%

Switched-capacitor voltage buck converter with variable step-down and switching frequency controllers for low-power and high-efficiency IoT devices

Matsuzuka

Kanzaki

Matsumoto

et al. 2023

Jpn. J. Appl. Phys.

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“…Several ELV circuit design techniques have been studied. [33][34][35][36][37][38][39][40][41][42] Matsuzuka et al reported an ELV ring oscillator (ROSC) using self-bias inverters (SBINVs) as a clock generator for the cold-start operation of a PMS. 33) The ROSC operated at an extremely low supply voltage of 42 mV.…”

Section: Introductionmentioning

confidence: 99%

A self-bias NAND gate and its application to non-overlapping clock generator for extremely low-voltage CMOS LSIs

Sebe¹,

Matsumoto²,

Matsuzuka³

et al. 2021

Jpn. J. Appl. Phys.

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This paper presents a self-bias NAND (SBNAND) gate and its application to a non-overlapping (NOL) clock generator for extremely low-voltage CMOS LSIs. The SBNAND, consisting of a main NAND gate and feedback inverter, improves the output performance at extremely low supply voltage V DD by controlling the body-bias voltages V BS of the main NAND gate. Measurements of a proof-of-concept chip demonstrated that our proposed NOL clock generator using SBNANDs can operate at the extremely low V DD of 60 mV.

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“…However, when the input voltage becomes low, the OSC is not able to oscillate correctly because the voltage gain of the delay cells, or CMOS inverters, decreases as the supply voltage decreases. Several low-voltage OSCs have been reported [25][26][27][28][29][30]. Matsuzuka et al reported a ring oscillator (ROSC) that can oscillate at a 42-mV supply voltage [27].…”

Section: Introductionmentioning

confidence: 99%

“…As thus, low-voltage ROSCs have been intensively studied to realize extremely low-voltage energy harvesting systems. In light of this background, we proposed an ROSC circuit capable of operating at extremely low supply voltage [30]. The proposed ROSC consists of dedicated low-voltage stacked body bias inverters (SBBIs) that are based on the conventional SBI and SI.…”

Section: Introductionmentioning

confidence: 99%

“…The proposed inverter employs the advantages of both SBI and SI to oscillate at extremely low supply voltage. In contrast to our previous work [30], here, we discuss its circuit operation and analyze its effectiveness in more detail. In addition, we fabricated a proof-of-concept chip in a 0.18-m CMOS process to demonstrate the extremely low voltage performance of our ROSC.…”

Section: Introductionmentioning

confidence: 99%

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A 35-mV supply ring oscillator consisting of stacked body bias inverters for extremely low-voltage LSIs

Nishi

Matsumoto

Kuroki

et al. 2021

IEICE Electron. Express

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This paper proposes a ring oscillator (ROSC) for extremely low-voltage LSI applications. The ROSC consists of dedicated low-voltage stacked body bias inverters (SBBIs) that are based on the conventional selfbias inverter (SBI) and stacked inverter (SI). The proposed SBBI employs the advantages of both SBI and SI to oscillate at extremely low supply voltage. The voltage gain of the proposed SBBI is improved by controlling main inverter's supply (DD and Gnd) and body-bias voltages, by using stacked and feedback inverters. The novelty of our proposed SBBI is in the combination of the conventional low-voltage circuit design techniques and its demonstration at extremely low supply voltage. Simulated and measured results in a 0.18-m CMOS process with deep n-well option demonstrated that the proposed ROSC can operate at extremely low supply voltage of 35 mV and generate a clock with a 88% voltage swing from an input supply voltage of 50 mV. To the best of the authors' knowledge, this is the lowest supply voltage CMOS ring oscillator ever reported.

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A 34-mV Startup Ring Oscillator Using Stacked Body Bias Inverters for Extremely Low-Voltage Thermoelectric Energy Harvesting

Cited by 7 publications

References 14 publications

Switched-capacitor voltage buck converter with variable step-down and switching frequency controllers for low-power and high-efficiency IoT devices

Switched-capacitor voltage buck converter with variable step-down and switching frequency controllers for low-power and high-efficiency IoT devices

A self-bias NAND gate and its application to non-overlapping clock generator for extremely low-voltage CMOS LSIs

A 35-mV supply ring oscillator consisting of stacked body bias inverters for extremely low-voltage LSIs

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