AMD announced a new chipset for 900-MHz digital spread spectrum cordless telephones, the fastest-growing segment in the North American cordless telephone market. Developed to give OEMs more design options at a lower cost with a faster time-to-market, the chipset consists of the Am79C440 direct sequence spread spectrum (DSSS) controller chip, and the Am79RF440 radio transceiver chip. The chipset allows customers to create a variety of products using a common chipset by programming the onboard ROM to enable different feature sets.

"Our OEM customers told us they wanted the flexibility to program a variety of features into different models while limiting the variety of parts they need to purchase," said David Rosado, MTS marketing in AMD's Communication Products Division. "The Am79C440 gives these OEMs the option of enabling different features for different models instead of having to select a different chip for each configuration. Together with the Am79RF440 transceiver, this chipset gives OEMs everything they need to design feature-rich, high-performance 900-MHz spread-spectrum phones while simplifying purchasing, inventory and production and lowering the total bill of materials."

The Am79C440 DSSS controller is a highly integrated design which performs protocol, data formatting, audio processing and peripheral functions for a DSSS handset or base station application. It features an on-chip 8051-class microcontroller, a flexible RF interface, and a receive signal strength indicator. Special audio features include a CCITT G.721 compliant ADPCM codec, programmable noise suppression, DTMF and ringing tone generators and a flexible audio interface, including a 16 Ohm speaker driver.

The Am79C440 DSSS controller also offers value-added features such as 1.25 K byte total SRAM, a serial port, a 36 key scanner and a watchdog timer. The Am79C440 controller features built-in power management, a single 3-V supply, CPU slowdown and oscillator shutdown which give low power consumption. The controller also features battery level detection to alert users of low battery conditions. A device with a PhoX^TM controller and Flash is available for development and allows for easy software development on the final board.

The Am79RF440 radio transceiver chip compliments the controller chip. The Am79RF440 integrates all of the transmit and receive functions required in a US900 DSSS digital cordless transceiver architecture, operating in the 902-928 MHz ISM band. The Am79RF440 is optimized for low power consumption and can turn off internal blocks when not in use to conserve battery life and extend talk time. When paired with the Am79C440 baseband controller, designers are able to create designs that offer unparalleled performance and significant system cost advantages for their 900-MHz spread spectrum product portfolio.

We don't often think of AMD and analog in the same sentence. Here, however, is the perfect example of a company using their developed smarts at both ends of the engineering feeding chain to produce a total solution. The Am79RF440 radio transceiver [which AMD say here "compliments" (sic) the controller] is a fairly straightforward 900-MHz ISM block with the sleep mode on the transmitter side so that the handset will always be ready to receive. The controller's biggest plus is the variety of features that can be programmed, or not, for different marketing levels of completed phones. That makes the design team's job at the OEM so much simpler when they are asked to produce 3 or 4 different models. The price of these parts is also right on for the competitive but fast growing market for spread-spectrum solutions for portable phones.

The Am79C440 controller is in either a 68-Pin PLCC or 100-pin PQFP, is sampling (production August 1998) and is priced at $5.95 for 100,000-piece lots. The Am79RF440 transceiver is in a 48-Pin thin PQFP, is sampling (production August 1998) and is priced at $3.95 in 100,000-piece lots.