By stripping out the higher-layer networking support and complexity of Bluetooth, ZigBee, 27-MHz and 900-MHz wireless technologies, Cypress keeps the current draw of its WirelessUSB LS radio in sleep mode below 1 microamp and its price at about $2, with plans to cut it to $1 quickly, the company said.

"There are some powerful networking solutions out there," said Norm Taffe, managing director of the wireless business unit at Cypress (San Jose, Calif.), referring to Bluetooth and ZigBee. "But they really have a lot of overhead. We're targeting a simpler marketplace with a lower-cost solution. None of the others are even discussing $2 yet."

The CYWUSB6934 chip is the second in Cypress' WirelessUSB lineup, which the company hopes will form a de facto standard for low-cost, low-power point-to-point and point-to-multipoint communications, Taffe said. The first EX chip, announced last November, is in production. Customers include keyboard maker NMB Technologies Corp.

Priced at $3.90, the EX is suited to the high side of the general target market, said Taffe, while the LS version "is very much targeted at 27-MHz device replacement. It's at a much more aggressive price point." The lower cost corresponds to lower data rates. Where the EX can reach rates above 200 kbits/second, the LS supports a maximum rate of 62 kbits/s.

The single-chip baseband-plus-radio device attaches directly to an antenna and outputs downconverted data via a four-pin SPI interface. "We've put a complete DSSS [direct sequence spread spectrum] baseband on it," said Paul Beard, chief technology officer of Cypress' Wireless Business Unit. "It renders fully error-corrected data over the SPI link so you don't need error correction or complex protocols done externally."

The new LS also includes dual DSSS basebands and a latency of under 4 milliseconds. Beard said the dual basebands allow a mouse and a keyboard to operate simultaneously while CDMA allows both to use the same channel while operating. CDMA also helps minimize latency. "That is another big reason we chose the CDMA/DSSS system, as there's no synchronization required on the channel between the two ends," said Beard.

The battery life of a system using the LS would be six to nine months, vs. more than six months for a system with ZigBee or between two and four months for a system with Bluetooth, Taffe said.

First silicon of the CYWUSB6934 is sampling now, and production is scheduled for October. A development kit is also sampling now for $495 and will also be in production by October. A transmit-only version of the device, the CYWUSB6932, is available for $2.20.

Cypress said the transmit-only version will cost $1 a year from now, with the reduction possibly resulting from a process shrink that takes the 2.7/3.3-volt device produced in a 0.25-micron process to a 1.8-V device produced in a 0.13-micron process. A $1 version of the full transceiver will be available six months later.

By: DocMemory
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