The circuit shown in the figure is suggested by ON Semiconductor (www.onsemi.com), based on its NCP4896 integrated circuit. It is an amplifier that can supply 1 W of power in BTL configuration with a load of 8 ohms from a 5 V supply. This circuit also supplies 250 mW with a 2.6 V supply and 90 mW with a 32 ohms load. and 5 V power supply. The device provides high audio quality requiring few external components. We also found the shutdown feature for low consumption from external logic. The supply voltage range is from 2.2 V to 5.5 V and the enclosure of the integrated circuit is 9-pin Flip-Chip. The device can also excite capacitive loads up to 1 nF and I have it externally configurable. As the circuit has excellent PSRR, it can be powered directly by a battery without the need to insert an LDO.
