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STMicroelectronics' STw5095 Low Power Stereo Audio/Voice Codec

STMicroelectronics has announced the STw5095 low power stereo audio/voice codec - featuring integrated amplifiers for headphones and hands free - which is designed as a compact and flexible solution for delivering high-quality audio in the low voltage conditions of battery-powered multimedia products and mobile phones. It is cost-optimized for voice and audio codec operation, and requires few external components, minimizing PCB area.

The STw5095 provides high audio quality analog stereo mixing, recording and playback capability, with three Line inputs and two direct differential microphone inputs. Audio flows are digitized with 20-bit resolution at between 8 and 96kHz, the ADC giving 93dB dynamic range and 0.001% THD, with full scale output at 2.7V. The output stereo DAC operates independently over the same data rate, with a 95dB dynamic range and 0.02% THD.

With its extended master clock range of between 4MHz and 32MHz, asynchronous digital input and output data rates, and compatibility with a range of audio data serial interfaces including I2S, SPI and PCM, the codec is designed to fit easily into most low voltage audio systems. Voice control and recording is supported by an 8/16kHz voice codec with embedded channel filters.

The stereo DAC outputs and multiple analog inputs are selectable and mixable; mixed signals can be connected to the chip's multiple output channels or to the ADC. Control registers for switching and gain control, and for the control of the on-chip bass/treble/volume DSP in the digital audio flow, are accessed through a selectable I2C or SPI compatible interface.

Embedded amplifiers can directly drive stereo headphones (2 x 40mW into 16 ohms, with a 40dB gain range) using a phantom ground configuration to eliminate coupling capacitors, and also drive a separate 500mW hands free/loudspeaker output. An independent stereo differential/single Line Out with gain control is provided.

The STw5095 can use the same 2.4V to 2.7V supply for all of its functions, or it can use different power supplies for its digital and analog circuits, and for the loudspeaker driver, to achieve optimum performance. Typical power consumption for playback is 23mW, and just 1µW in Standby. It is available now in a 5 x 5mm, 1.2mm high, TFBGA64 package with 0.5mm ball pitch.



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