STM Chip Turns Mobile Gadgets Into Voice Recorders

As I've been mercilessly flamed for in the past, I still haven't found my personal killer app that will inspire me to drop hundreds of dollars on a PDA that does little more for me than a 50-cent notepad and an address book. However, STMicroelectronics is putting forth a new chip that may add capabilities to PDAs and other mobile devices and may push them closer to the top of my wish list. The company's stereo digital-to-analog converter chip includes a voice coder/decoder (CODEC) to add voice recording and playback portable electronics that also include digital music players, FM radios and mobile phones. Called STw5094, the new converter chip consumes 13mW operational and 1mW standby to keep from draining the juice out of the old AAAs. The chip has an 18-bit delta sigma stereo digital-to-analog converter with multirate sampling frequencies of 8kHz, 11.025kHz, 22.05kHz, 44.1kHz and 48kHz. Samples are fed into the device through an I2S bus from a digital decoder and stereo headset earpiece drivers are also integrated into the design. The built in voice CODEC connects directly to the microphone and earpieces and includes digital programming of all internal analog op amps.

The STw5094 also includes an analog input multiplexer to select either the decoded digital music or stereo FM radio signal to be directed to the internal stereo headphone amplifiers. The headset amplifiers in the chip deliver 2x20mW into 30ohms with a 92dB dynamic range, producing 0.01% total harmonic distortion at 16.5mW output power. Packaged in a 6x6mm TFBGA36 package, the STw5094 operates on a 1.8 to 3.3V digital supply and 2.7V to 3.3V analog supply. For evaluation, ST provides a demo board, which includes a mono FM radio receiver and an MP3 player based on the STA015 MP3 decoder chip. The board connects to a Windows98 PC through a plug and play USB port and is supplied with PC control software that give you interactive schematics and register display windows. So there you have it. When I can carry around a PDA that also acts as an MP3 player, digital voice recorder, FM radio, contact manager, notepad, and lets me send and receive wireless email without signing up for yet another email address that I have to check, you'll see me standing in line at CompUSA. Oh yeah, it also needs to cost under $300 and a digital camera attachment and rechargeable batteries would be nice. Good Lord, here come the flames...