Yasuyuki OKUMA

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 Po-Hung CHEN Kazunori WATANABE Makoto TAKAMIYA Takayasu SAKURAI 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 2011/06/01
Vol. E94-C  No. 6  pp. 938-944
Type of Manuscript:  Special Section PAPER (Special Section on Analog Circuits and Related SoC Integration Technologies)
Category: 
Keyword: 
low dropout regulator, digital control, low voltage, 
 Summary | Full Text:PDF
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 Yu PU Koichi ISHIDA Yoshikatsu RYU Yasuyuki OKUMA Po-Hung CHEN Takayasu SAKURAI Makoto TAKAMIYA 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 2011/06/01
Vol. E94-C  No. 6  pp. 953-959
Type of Manuscript:  Special Section PAPER (Special Section on Analog Circuits and Related SoC Integration Technologies)
Category: 
Keyword: 
DC-DC converter, low ripple, low voltage, pulse density modulation, pulse width modulation, switched-capacitor, 
 Summary | Full Text:PDF
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 Yasuyuki OKUMA Yoshikatsu RYU Makoto TAKAMIYA Takayasu SAKURAI 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 2011/04/01
Vol. E94-C  No. 4  pp. 598-604
Type of Manuscript:  Special Section PAPER (Special Section on Circuits and Design Techniques for Advanced Large Scale Integration)
Category: 
Keyword: 
charge pumps, switched capacitor, startup, boost converter, low voltage, 
 Summary | Full Text:PDF
0.7-GHz-Bandwidth DS-UWB-IR System for Low-Power Wireless Communications
Ryosuke FUJIWARA Akira MAEKI Kenichi MIZUGAKI Goichi ONO Tatsuo NAKAGAWA Takayasu NORIMATSU Masaru KOKUBO Masayuki MIYAZAKI Yasuyuki OKUMA Miki HAYAKAWA Shinsuke KOBAYASHI Noboru KOSHIZUKA Ken SAKAMURA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2008/02/01
Vol. E91-B  No. 2  pp. 518-526
Type of Manuscript:  PAPER
Category: Wireless Communication Technologies
Keyword: 
impulse radio, LR-WPAN, UWB, wireless sensor networks, 
 Summary | Full Text:PDF
+3 V/-3 V Operation 1.2 Gbps Write Driver for Hard Disk Drives
Yasuyuki OKUMA Kenji MAIO Hiroyasu YOSHIZAWA 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 2004/04/01
Vol. E87-C  No. 4  pp. 578-581
Type of Manuscript:  Special Section PAPER (Special Section on Low-Power System LSI, IP and Related Technologies)
Category: 
Keyword: 
low-voltage, hard disk drive, write driver, 
 Summary | Full Text:PDF