Audio IC suits portable multimedia apps

Atmel Corp. has released its AT73C240 Audio Companion IC for portable multimedia applications. Manufactured on Atmel's low-cost mainstream CMOS process, the AT73C240 integrates an audio quality 20bit Stereo DAC and an up to 1W audio power amplifier. The AT73C240 is suited for portable applications where a high-quality audio interface is required (i.e. new-generation mobile phones, PDAs, palmtop computers, digital still cameras, portable multimedia devices and music players).

The AT73C240 integrates a complete high-performance stereo audio DAC delivering a 90dB dynamic range, followed by a 32Ω stereo headset driver with programmable volume control and mute function. The stereo DAC comprises a multibit sigma-delta modulator with dither, continuous time analog filters and analog output drive circuitry. The master clock is 256 or 384 times the sampling frequency, allowing the choice of input data rate up to 50kHz, including standard audio rates of 48, 44.1-, 32-, 16- and 8kHz. The stereo 32Ω headset drivers also include a mixer for a pair of stereo inputs.

The DAC outputs can also be played back through a mixer buffer stage to the integrated audio power amplifier. The mono buffer stage can also receive the mixing of the stereo inputs as well as the differential monaural auxiliary input (which can be, for example, from a voice codec output driver in a mobile phone). The audio power amplifier is a dual-mode AB class amplifier with differential output and programmable volume control. In full power mode, it is capable of driving an 8Ω loudspeaker at maximum power of 1W at 5.5V supply and 440mW at 3.6V supply. The volume, mute, power down, de-emphasis controls and 16-, 18-, 20bit audio formats are digitally programmable via a 4-wire SPI bus and the digital audio data is provided through a multiformat I?S interface.

Atmel offers the AT73C240 in a 5mm x 5mm, 32-pin QFN package to satisfy portable device manufacturers' minimum space requirements. It is available, now mounted on a reference design board or as engineering samples. Production quantities are also available, with a reference price below $ 0.80 in large quantities.

- Henri Arnold
EE Times Europe