Atmel Corp.’s AT73C240 Audio Companion IC, manufactured on its low-cost mainstream CMOS process, integrates an audio quality 20-bit Stereo DAC and an up to 1W audio power amplifier. Suited to portable applications such as new-generation mobile phones, PDAs, palmtop computers, digital still cameras, portable multimedia devices, and music players, the AT73C240’s integrated DAC delivers a 90dB dynamic range, followed by a 32Ω stereo headset driver with programmable volume control and mute function. The stereo DAC comprises a multi-bit 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 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-, 20-bit audio formats are digitally programmable via a 4-wire SPI bus and the digital audio data is provided through a multi-format I2S interface.
Atmel Corp.
www.atmel.com
Caption
Suited to portable applications such as mobile phones, PDAs, digital still cameras, portable multimedia devices, and music players, the AT73C240 Audio Companion IC integrates an audio quality 20-bit Stereo DAC and an up to 1W audio power amplifier.
