0.18-V input charge pump with forward body biasing in startup circuit using 65nm CMOS. - Po-Hung Chen; Koichi Ishida; Xin Zhang 025; Yasuaki Okuma; Yoshikatsu Ryu; Makoto Takamiya; Takayasu Sakurai (CICC, 2010)

0.5-V input digital LDO with 98.7% current efficiency and 2.7-µA quiescent current in 65nm CMOS. - Yasuyuki Okuma; Koichi Ishida; Yoshikatsu Ryu; Xin Zhang 025; Po-Hung Chen; Kazunori Watanabe; Makoto Takamiya; Takayasu Sakurai (CICC, 2010)

A 80-mV input, fast startup dual-mode boost converter with charge-pumped pulse generator for energy harvesting. - Po-Hung Chen; Koichi Ishida; Xin Zhang 025; Yasuyuki Okuma; Yoshikatsu Ryu; Makoto Takamiya; Takayasu Sakurai (A-SSCC, 2011)

A 95mV-startup step-up converter with Vth-tuned oscillator by fixed-charge programming and capacitor pass-on scheme. - Po-Hung Chen; Koichi Ishida; Katsuyuki Ikeuchi; Xin Zhang 025; Kentaro Honda; Yasuyuki Okuma; Yoshikatsu Ryu; Makoto Takamiya; Takayasu Sakurai (ISSCC, 2011)

0.18-V Input Charge Pump with Forward Body Bias to Startup Boost Converter for Energy Harvesting Applications. - Po-Hung Chen; Koichi Ishida; Xin Zhang 025; Yasuyuki Okuma; Yoshikatsu Ryu; Makoto Takamiya; Takayasu Sakurai (IEICE Trans. Electron., 2011)

0.5-V Input Digital Low-Dropout Regulator (LDO) with 98.7% Current Efficiency in 65 nm CMOS. - Yasuyuki Okuma; Koichi Ishida; Yoshikatsu Ryu; Xin Zhang 025; Po-Hung Chen; Kazunori Watanabe; Makoto Takamiya; Takayasu Sakurai (IEICE Trans. Electron., 2011)

A Variable Output Voltage Switched-Capacitor DC-DC Converter with Pulse Density and Width Modulation (PDWM) for 57% Ripple Reduction at Low Output Voltage. - Xin Zhang 025; Yu Pu; Koichi Ishida; Yoshikatsu Ryu; Yasuyuki Okuma; Po-Hung Chen; Takayasu Sakurai; Makoto Takamiya (IEICE Trans. Electron., 2011)

A 120-mV input, fully integrated dual-mode charge pump in 65-nm CMOS for thermoelectric energy harvester. - Po-Hung Chen; Koichi Ishida; Xin Zhang 025; Yasuyuki Okuma; Yoshikatsu Ryu; Makoto Takamiya; Takayasu Sakurai (ASP-DAC, 2012)

A 0.45-V input on-chip gate boosted (OGB) buck converter in 40-nm CMOS with more than 90% efficiency in load range from 2µW to 50µW. - Xin Zhang 025; Po-Hung Chen; Yoshikatsu Ryu; Koichi Ishida; Yasuyuki Okuma; Kazunori Watanabe; Takayasu Sakurai; Makoto Takamiya (VLSIC, 2012)

Startup Techniques for 95 mV Step-Up Converter by Capacitor Pass-On Scheme and VTH-Tuned Oscillator With Fixed Charge Programming. - Po-Hung Chen; Koichi Ishida; Katsuyuki Ikeuchi; Xin Zhang 025; Kentaro Honda; Yasuyuki Okuma; Yoshikatsu Ryu; Makoto Takamiya; Takayasu Sakurai (IEEE J. Solid State Circuits, 2012)

An 80 mV Startup Dual-Mode Boost Converter by Charge-Pumped Pulse Generator and Threshold Voltage Tuned Oscillator With Hot Carrier Injection. - Po-Hung Chen; Xin Zhang 025; Koichi Ishida; Yasuyuki Okuma; Yoshikatsu Ryu; Makoto Takamiya; Takayasu Sakurai (IEEE J. Solid State Circuits, 2012)

A 1-V-Input Switched-Capacitor Voltage Converter With Voltage-Reference-Free Pulse-Density Modulation. - Xin Zhang 025; Yu Pu; Koichi Ishida; Yoshikatsu Ryu; Yasuyuki Okuma; Po-Hung Chen; Kazunori Watanabe; Takayasu Sakurai; Makoto Takamiya (IEEE Trans. Circuits Syst. II Express Briefs, 2012)

A low voltage buck DC-DC converter using on-chip gate boost technique in 40nm CMOS. - Xin Zhang 025; Po-Hung Chen; Yoshikatsu Ryu; Koichi Ishida; Yasuyuki Okuma; Kazunori Watanabe; Takayasu Sakurai; Makoto Takamiya (ASP-DAC, 2013)

A 0.6 V Input CCM/DCM Operating Digital Buck Converter in 40 nm CMOS. - Xin Zhang 025; Po-Hung Chen; Yasuyuki Okuma; Koichi Ishida; Yoshikatsu Ryu; Kazunori Watanabe; Takayasu Sakurai; Makoto Takamiya (IEEE J. Solid State Circuits, 2014)