STMicroelectronics today unveiled an innovative modem chipset that connects to a Universal Serial Bus (USB) port, bringing an outstanding combination of performance, small size, low power consumption and ease of use. Called Pegas.usB, the new modem chipset is compliant with the latest International Telecommunication Union (ITU) V.90 standard for connection speeds up to 56Kbit/s and consists of just two integrated circuits -- ST7554 USB World Modem Controller and the STLC7550 Modem Analog Front End. Both chips are housed in compact Thin Quad Flat Pack (TQFP) packages.

Thanks to the small size of the circuit a complete modem can be housed inside a connector sized "dongle" that is compact and inexpensive to manufacture. Power consumption is less than 50mA operational and 500uA in suspend mode so it can be supplied from the bus line respecting fully the USB standard. Taking full advantage of Windows98 and the USB plug and play capability, Pegas.usB based modems will also need no hardware installation and be simple to use, minimizing calls to customer support.

"USB is a key technology for the new Windows98 PCs now being shipped", comments ST's Pietro Palella, Director of ST's Wireline Communications Division, "because it brings a simple approach to connecting peripherals. ST is taking advantage of the USB port to deliver the most compact and user friendly modem solution."

For the Pegas.usB chipset ST designers chose the patented "USB-Modio" host based modem and system software technology developed by Smart Link. USB-Modio moves modem functions previously performed by a digital signal processor (DSP) to the computer's own host processor. Users benefit from this approach because the modem's program code is stored on the computer's hard disk, so it can be upgraded quickly and easily to new standards by downloading new code through the network. This technique also lowers the modem's power consumption, which is especially important in portable applications. With current generation Pentium processors, the modem overhead is practically undetectable by the user; the recommended minimum is a 200MHz Pentium MMX with 16MB of RAM.

In addition to complying with the V.90 56Kbit/s standard, the Pegas.usB modem/fax chip set is also ready for the V.80 videophone standard and includes support for automatic identification of voice, fax or modem calls. It also supports a complete range of modem fall back modes for legacy compatibility (V.34bis, V.34, V.32bis. V.32, V.22bis, V.22, V.23, V.21, Bell 103 and Bell 212A), all fax modes currently used (V.17, V.27ter, V.29 & fax class 1) and all of the commonly used protocols for error correction and data compression (V.42, V.42bis, MNP2 ,3, 4, 5).

ST also announced that in the first quarter of 1999 a second generation Pegas.usB chipset will be available that includes a transformerless solid-state Data Access Arrangement (DAA), the circuit that interfaces the modem to the phone line. Ideal for compact dongle type packages, this solution is programmable to meet different national telecom standards, allowing modem manufacturers to use a single design for markets in many different countries. A third version with voice speakerphone and cellular support capability is scheduled for introduction in the second quarter 1999 and solutions for integrating the V.90 modem with high speed xDSL solutions from ST are planned.

In addition to samples of the devices and documentation ST is also offering a complete evaluation package including a ready-to-use "dongle" type modem and all of the software. Click here for more details. Complete schematics and engineering data for manufacturing the modem subsystem are available to selected modem and computer makers.

This product had to come; it is made possible by the general acceptance, and now adoption, of USB technology and also by the work of Smart Link (Netanya, Israel) in preparing the way with their USB-Modio to allow the host PC processor to take over the work of the DSP that would otherwise have to be in the modem. This permits STM to basically concentrate on the modem itself. Their solution is convincing, with the modem controller offering just about total coverage of modem standards for data, voice and fax. The OEM can therefore develop just one "dongle" device for the world market as far as the electronics is concerned although there would need to be a number of different line connectors. The chipset appears to fully comply with the needs and requirements of the USB specification and the power consumptions are modest. And the idea of a hardware-free installation for a modem is something that IT personnel will swoon over.

This will be a highly successful chipset for STM in this present form, and the future developments that they forsee in their product roadmap will also find ready market acceptance; certainly a cellular/laptop solution is urgently being looked for by more and more users. Covering xDSL standards in the same manner certainly sounds achievable although the line drive requirements would have suggested to me that bus powering would not be possible. The first commercial modems using this present chipset should be around within a few months.