A low-ripple charge pump with continuous pumping current control

Author

Wu, Chi-Hao ; Chen, Chern-Lin

Author_Institution

Grad. Inst. of Electron. Eng., Nat. Taiwan Univ., Taipei

fYear

2008

fDate

10-13 Aug. 2008

Firstpage

722

Lastpage

725

Abstract

This paper presents a low-ripple regulated charge pump with continuous pumping current control. Output voltage is continuously regulated for full-range load variation. Multi-phase charge pump can be easily achieved under the constant pumping frequency control scheme. In this way, the output voltage ripple can be minimized further. An experimental chip has been fabricated in a 0.5 mum CMOS process and the active area is 0.3mm². The measured ripple voltage is less than 28 mV at 20 mA load current with 100 kHz pumping frequency. The implemented chip is designed for portable TFT-LCD drivers. It delivers a regulated voltage from 4.5 V to 5 V with 1 mu F flying and load capacitors.

Keywords

CMOS integrated circuits; driver circuits; liquid crystal displays; thin film transistors; CMOS process; continuous pumping current control; current 20 mA; low-ripple charge pump; multiphase charge pump; portable TFT-LCD drivers; size 0.5 mum; voltage 4.5 V to 5 V; CMOS process; Capacitors; Charge pumps; Current control; Current measurement; Frequency control; Frequency measurement; Load management; Semiconductor device measurement; Voltage measurement;

fLanguage

English

Publisher

ieee

Conference_Titel

Circuits and Systems, 2008. MWSCAS 2008. 51st Midwest Symposium on

Conference_Location

Knoxville, TN

ISSN

1548-3746

Print_ISBN

978-1-4244-2166-4

Electronic_ISBN

1548-3746

Type

conf

DOI

10.1109/MWSCAS.2008.4616901

Filename

4616901