STMicroelectronics (Geneva, Switzerland) has introduced a combined audio-DAC (digital-to-analog converter) and line-driver IC that can supply the audio Line-Out connection in set-top boxes, DVD players and other consumer devices.
The TS4657 is an soc with internal power management unit producing a 2.2Vrms audio-output signal, thus eliminating the need for a separate high-voltage power supply to drive the Line-Out output. ST's design also integrates four capacitors for the charge pumps, and its ability to generate both negative and positive voltages means there's no need for the audio signal to be referenced to ground, doing away with the need for a decoupling capacitor in the audio-signal line too.
This part caters for voltages from 3.0V to 5.5V. With an operating current of 7.4mA, ST claims the TS4657 has the potential to cut power consumption by two thirds compared to the nearest competing device. Other stated characteristics include a 93dB dynamic range, 80dB Power Supply Rejection Ratio (at 217Hz), and 81dB THD+N at 0dBFS. The TS4657 is already in production in a 4 x 4mm QFN20 package.