Title :
An Integrated 1.2V-to-6V CMOS Charge-Pump for Electret Earphone
Author :
Tseng, Chun-Yen ; Chen, Shih-Chieh ; Shia, Tim K. ; Huang, Po-Chiun
Author_Institution :
Nat. Tsing Hua Univ., Hsinchu
Abstract :
This work proposes a new charge pump design that achieves a high set-up ratio for electret earphone driving circuits. The voltage pumping cell is based on Cockcroft-Walton topology to achieve small area with constant MOS capacitor value under low system voltage operation. A 6-V output voltage is regulated by a PFM-based loop. This loop includes a new switched-capacitor divider as a part of the sensing circuitry. All the components are integrated in a standard 0.18 mum CMOS. Measurement results show that with 1.2 V supply, the output voltage is around 6 V with 30 mV output ripple. The maximum output driving current is up to 0.7 mA.
Keywords :
CMOS integrated circuits; MOS capacitors; earphones; electrets; electric charge; low-power electronics; network topology; pulse frequency modulation; pumps; switched capacitor networks; voltage control; voltage dividers; voltage multipliers; CMOS integrated circuit; Cockcroft-Walton topology; PFM-based loop; constant MOS capacitor value; electret earphone driving circuits; high set-up ratio; integrated CMOS charge-pump design; low system voltage operation; size 0.18 mum; standard CMOS process; switched-capacitor divider; voltage 1.2 V to 6 V; voltage pumping cell; CMOS technology; Charge pumps; Circuit topology; Clocks; Digital control; Electrets; Headphones; Low voltage; MOS capacitors; Virtual manufacturing; CMOS integrated circuit; charge pump circuit; electret earphone; high setup-ratio;
Conference_Titel :
VLSI Circuits, 2007 IEEE Symposium on
Conference_Location :
Kyoto
Print_ISBN :
978-4-900784-05-5
Electronic_ISBN :
978-4-900784-05-5
DOI :
10.1109/VLSIC.2007.4342678
