Integrated DAC and line-out driver saves at least four external components and cuts typical power consumption by over two thirds
Geneva, September 25, 2009 - Combined audio converter/driver ICs are simplifying the design of set-top boxes and other consumer audio/video products, but the new TS4657 from STMicroelectronics (NYSE: STM), a leading provider of digital audio ICs, improves on this by saving additional external components while reducing power consumption and improving sound quality.
ST''s new TS4657 is a single chip combining audio-DAC (digital-to-analog converter) and line-driver functions to feed the audio Line-Out connection of set-top boxes, DVD players, portable multimedia devices, sound cards, or similar equipment. The Line Out provides a direct connection to drive an external home amplifier.
The IC uses an internal power management unit to produce a 2.2Vrms audio-output signal for voltages from 3.0V to 5.5V, eliminating the need for a separate high-voltage power supply to drive the Line-Out output. Similar devices typically require four external capacitors for the charge pumps but ST''s high-frequency design integrates these on-chip, thereby saving board space and bill-of-materials costs. In addition, the ability to generate negative and positive voltages allows the audio signal to be referenced to ground, which saves the need for a decoupling capacitor in the audio-signal line.