A speaker driver for single phase supply Class G & I

The paper describes the design and implementation of a speaker driver applied to Class G/Class I with single phase power supply. Gain expanding and compressing technology are employed in signal processing circuit to optimize power dissipation. Experimental results using 0.18μm N-well CMOS show that it can obtain less than 0.006% THD at low power range and less than 0.4% at medium power range with a 1 KHz sine wave signal. It can get maximum output power of 360mW at a load of 8Ω. The power efficiency is about twice as that of traditional class AB driver at the power range of 80mW and more than 18% improvement at higher power range.