Title :
A voltage-reference-free pulse density modulation (VRF-PDM) 1-V input switched-capacitor 1/2 voltage converter with output voltage trimming by hot carrier injection and periodic activation scheme
Author :
Zhang, Xin ; Pu, Yu ; Ishida, Koichi ; Ryu, Yoshikatsu ; Okuma, Yasuyuki ; Chen, Po-Hung ; Watanabe, Kazunori ; Sakurai, Takayasu ; Takamiya, Makoto
Author_Institution :
Univ. of Tokyo, Tokyo, Japan
Abstract :
A 1-V input, 0.45-V output switched-capacitor (SC) 2:1 voltage converter is developed in 65-nm CMOS. A proposed voltage-reference-free pulse density modulation (VRF-PDM) increased the efficiency from 17% to 73% at 50-μA output current by reducing the pulse density and eliminating the voltage reference circuit. An output voltage trimming by the hot carrier injection to a comparator and a periodic activation scheme of the SC converter are also proposed to solve the problems attributed to VRF-PDM.
Keywords :
CMOS integrated circuits; comparators (circuits); hot carriers; power convertors; pulse modulation; switched capacitor networks; CMOS; SC converter; comparator; current 50 muA; efficiency 17 percent to 73 percent; hot carrier injection; output voltage trimming; periodic activation scheme; size 65 nm; switched-capacitor; voltage 0.45 V; voltage 1 V; voltage converter; voltage reference circuit; voltage-reference-free pulse density modulation; Density measurement; Hot carrier injection; Human computer interaction; Modulation; Pulse measurements; Switches; Voltage measurement;
Conference_Titel :
VLSI Circuits (VLSIC), 2011 Symposium on
Conference_Location :
Honolulu, HI
Print_ISBN :
978-1-61284-175-5
