Title :
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
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;
Conference_Titel :
Circuits and Systems, 2008. MWSCAS 2008. 51st Midwest Symposium on
Conference_Location :
Knoxville, TN
Print_ISBN :
978-1-4244-2166-4
Electronic_ISBN :
1548-3746
DOI :
10.1109/MWSCAS.2008.4616901
