Expanding its portfolio of 3G TD-SCDMA technology solutions, Analog Devices, Inc. has unveiled its second-generation chipset for developers of 3G mobile handsets based on the time-division synchronous code-division multiple access (TD-SCDMA) low chip rate (LCR) air interface. The new SoftFone-LCR+ chipset provides support for enhanced multimedia functions such as 3-megapixel cameras, USB, multiformat audio encode/decode, wavetable MIDI and MP3 ringtones, as well as advanced video capture and playback and stereo audio codecs. The chipset enables dual-mode TD-SCDMA/GPRS operation and achieves full 384 kbps 3G performance, enabling faster download speeds, video streaming, video telephony and Web browsing capabilities. In addition, the SoftFone-LCR+ chipset also features the company’s RF transceiver, Othello-W, which offers the lowest call drop rates and best sensitivity available, ADI said. The SoftFone-LCR+ chipset has been demonstrated on a live TD-SCDMA network, successfully completing file transfers on a 384 kbps data connection, according to ADI.

The SoftFone-LCR+ chipset supports video algorithms such as MPEG4, H.263 and H.264 for screen sizes up to QVGA; stereo audio codecs including MP3, AAC+, WMA and others; and it offers 128-voice MIDI ringtones – all handled in software. The chipset also includes built-in support for up to 3-megapixel resolution cameras as well as USB. The chipset also supports full “boot from NAND” capability, so that cost-effective NOR-less designs for feature phones are possible.

The TD-SCDMA standard was proposed by the China Wireless Telecommunication Standards group (CWTS) and approved by the 3GPP (3rd Generation Partnership Project) as the low-chip-rate TDD standard of the 3G standard family. Designed for 1.6 MHz channels, it is compatible with 5 MHz unpaired 3G bands in any region of the world. TD-SCDMA can serve as a complement to W-CDMA deployments since it uses the same network backbone. Last month, Chinese telecom operators entered into a TD-SCDMA trial network and received 3G services. Analog Devices has been working closely with Datang Mobile, a leading company dedicated to the research and development of TD-SCDMA and the software provider for the SoftFone-LCR chipsets, and together the companies offer a series of solutions, which provide all the necessary hardware and software to develop a 3G TD-SCDMA phone suitable for volume production. In addition, the dual-mode TD-SCDMA software is provided by Datang Mobile and includes GPRS protocol stack software from Sasken Communication Technologies Ltd.

The SoftFone-LCR+ chipset supports all the critical functions required to build a TD-SCDMA handset, including the baseband signal processing and control, analog-interface functions and radio. It is based on the popular RAM-based SoftFone architecture also used in ADI’s GSM/GPRS, EDGE and W-CDMA chipsets. ADI’s SoftFone-LCR+ dual-mode chipset consists of five chips, including the AD6903 digital baseband processor that uses the company’s Blackfin Processor achieving 260 MHz along with an ARM9 microcontroller, to perform both the communications and audio/video signal processing tasks in a media-rich handset. The software-based approach of the SoftFone architecture enables terminal developers to maintain maximum software flexibility. Additionally, the SoftFone-LCR+’s AD6857 Stratos-T analog baseband and power management IC provides a full set of audio features, as well as efficient power management. The SoftFone-LCR+ chipset includes interfaces for cameras, color displays, IR, USB and SD/MMC, allowing handset manufacturers to create several designs with varying levels of feature sets for a wide range of phone models.

In addition, the SoftFone-LCR+ chipset includes the Othello-W direct-conversion radio transceiver, offering solid performance and flexibility for either LCR time division duplex (TDD) or W-CDMA frequency division duplex (FDD) terminals. For dual-mode operation, the chipset adds the Othello-G transceiver, which enables the world’s smallest GSM/GPRS radio.

The SoftFone-LCR+ chipset is sampling now and volume production is expected to begin in spring, 2007.