Title :
A 2.8V RWDM BTL Class-D power amplifier using an FGMOS comparator
Author :
Nandhasri, K. ; Ngarmnil, J. ; Moolpho, K.
Author_Institution :
Dept. of Electron. Eng., Mahanakorn Univ. of Technol., Bangkok, Thailand
Abstract :
This paper presents a design of an output stage based on Class-D amplifier techniques using rectangular wave delta modulation (RWDM) topology. This amplifier has a simple structure comprised only of a hysteresis comparator and output drivers. Thanks to the use of a multiple-input hysteresis comparator using floating-gate MOSFETs, the amplifier is capable of low voltage operation. On Alcatel 0.5 μm double poly CMOS process, this amplifier demonstrated up to 0.88W with 95% efficiency with a 2.8V power supply. This means implementation as a monolithic chip is possible, making this amplifier suitable for portable applications such as speaker driving circuits in mobile phones, hearing aids and other implantable medical devices.
Keywords :
CMOS analogue integrated circuits; audio-frequency amplifiers; comparators (circuits); delta modulation; driver circuits; low-power electronics; power amplifiers; 0.5 micron; 0.88 W; 2.8 V; 95 percent; Alcatel double poly CMOS process; FGMOS comparator; RWDM BTL Class-D power amplifier; bridge tied load; hysteresis comparator; implantable medical devices; low voltage operation; output drivers; rectangular wave delta modulation; speaker driving circuits; CMOS process; Delta modulation; Driver circuits; Hysteresis; Low voltage; MOSFETs; Operational amplifiers; Power amplifiers; Power supplies; Topology;
Conference_Titel :
Circuits and Systems, 2002. ISCAS 2002. IEEE International Symposium on
Print_ISBN :
0-7803-7448-7
DOI :
10.1109/ISCAS.2002.1010690
