19 May 2009

Atmel Audio-To-Analog Converter IC With Audio Amplifier

Atmel Corporation, a member of the ARM Connected Community,  has released  its AT73C240 Audio Companion IC for portable multimedia applications.

The AT73C240 can be used with Atmel's proprietary AVR microcontroller family or with its SAM and CAP ARM-based MCUs, allowing customers to get the highest audio quality at the lowest system cost, the company explained.

Manufactured on Atmel's low-cost mainstream CMOS process, the AT73C240 integrates an audio quality 20-bit Stereo DAC and an up to 1W audio power amplifier. The AT73C240 is ideally suited for portable applications where a high-quality audio interface is required, such as new-generation mobile phones, PDAs, palmtop computers, digital still cameras, portable multimedia devices and music players, the company said.

The AT73C240 integrates a complete high-performance stereo audio digital-to-analog converter delivering a 90 dB dynamic range, followed by a 32-Ohm 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 50 kHz, including standard audio rates of 48, 44.1, 32, 16 and 8 kHz. The stereo 32-Ohm 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 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 8-Ohm 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.