A 18.9-nA standby current comparator with adaptive bias current generator. - Kosuke Isono; Tetsuya Hirose; Keishi Tsubaki; Nobutaka Kuroki; Masahiro Numa (A-SSCC, 2011)

A low-power single-slope analog-to-digital converter with digital PVT calibration. - Yuji Osaki; Tetsuya Hirose; Keishi Tsubaki; Nobutaka Kuroki; Masahiro Numa (ICECS, 2012)

A 6.66-kHz, 940-nW, 56ppm/°C, fully on-chip PVT variation tolerant CMOS relaxation oscillator. - Keishi Tsubaki; Tetsuya Hirose; Yuji Osaki; Seiichiro Shiga; Nobutaka Kuroki; Masahiro Numa (ICECS, 2012)

A 32.55-kHz, 472-nW, 120ppm/°C, fully on-chip, variation tolerant CMOS relaxation oscillator for a real-time clock application. - Keishi Tsubaki; Tetsuya Hirose; Nobutaka Kuroki; Masahiro Numa (ESSCIRC, 2013)

A 0.21-V minimum input, 73.6% maximum efficiency, fully integrated voltage boost converter with MPPT for low-voltage energy harvesters. - Toshihiro Ozaki; Tetsuya Hirose; Takahiro Nagai; Keishi Tsubaki; Nobutaka Kuroki; Masahiro Numa (ESSCIRC, 2014)

A Fully On-Chip, 6.66-kHz, 320-nA, 56ppm/°C, CMOS Relaxation Oscillator with PVT Variation Compensation Circuit. - Keishi Tsubaki; Tetsuya Hirose; Yuji Osaki; Seiichiro Shiga; Nobutaka Kuroki; Masahiro Numa (IEICE Trans. Electron., 2014)

A 0.21-V minimum input, 73.6% maximum efficiency, fully integrated 3-terminal voltage converter with MPPT for low-voltage energy harvesters. - Toshihiro Ozaki; Tetsuya Hirose; Takahiro Nagai; Keishi Tsubaki; Nobutaka Kuroki; Masahiro Numa (ASP-DAC, 2015)

A 32-kHz Real-Time Clock Oscillator with On-Chip PVT Variation Compensation Circuit for Ultra-Low Power MCUs. - Keishi Tsubaki; Tetsuya Hirose; Nobutaka Kuroki; Masahiro Numa (IEICE Trans. Electron., 2015)

A 1.66-nW/kHz, 32.7-kHz, 99.5ppm/°C fully integrated current-mode RC oscillator for real-time clock applications with PVT stability. - Hiroki Asano; Tetsuya Hirose; Keishi Tsubaki; Taro Miyoshi; Toshihiro Ozaki; Nobutaka Kuroki; Masahiro Numa (ESSCIRC, 2016)

A fully integrated, 1-µs start-up time, 32-MHz relaxation oscillator for low-power intermittent systems. - Hiroki Asano; Tetsuya Hirose; Taro Miyoshi; Keishi Tsubaki; Toshihiro Ozaki; Nobutaka Kuroki; Masahiro Numa (NEWCAS, 2016)

A Highly Efficient Switched-Capacitor Voltage Boost Converter with Nano-Watt MPPT Controller for Low-Voltage Energy Harvesting. - Toshihiro Ozaki; Tetsuya Hirose; Takahiro Nagai; Keishi Tsubaki; Nobutaka Kuroki; Masahiro Numa (IEICE Trans. Fundam. Electron. Commun. Comput. Sci., 2016)

Sub-1-μs start-up time, 32-MHz relaxation oscillator for low-power intermittent VLSI systems. - Hiroki Asano; Tetsuya Hirose; Taro Miyoshi; Keishi Tsubaki; Toshihiro Ozaki; Nobutaka Kuroki; Masahiro Numa (ASP-DAC, 2017)

A Sub-1-µs Start-Up Time, Fully-Integrated 32-MHz Relaxation Oscillator for Low-Power Intermittent Systems. - Hiroki Asano; Tetsuya Hirose; Taro Miyoshi; Keishi Tsubaki; Toshihiro Ozaki; Nobutaka Kuroki; Masahiro Numa (IEICE Trans. Electron., 2018)