A high-efficiency 4/spl times/20 W monolithic audio amplifier for automobile radios using a complementary D-MOS BCD technology

A monolithic quad audio power amplifier which reduces power dissipation by 45% with a music signal compared to a standard class-AB amplifier is described. A new two-stage operational amplifier, capable of providing high output current, is used for each one of eight power amplifiers. In a bridge configuration, a common-loop mode control is performed exploiting a sample-and-hold circuit. A multipower bipolar-CMOS-DMOS (BCD) technology is employed with a push-pull rail-to-rail output stage and a low-loss power switch. Experimental results are presented.