Reference design for RF-transceiver enables fast development of 2.4 GHz systems for ISM band

2006-02-20

Atmel has introduced a reference design that addresses the need for cost-effective and flexible cable-replacement solutions. Featuring Atmel’s ATR2406 2.4 GHz Smart RF transceiver and the ATmega88 AVR(r) microcontroller, the reference design offers a complete solution for rapid system development. The proprietary Smart RF firmware implements an adaptive frequency-hopping protocol, enabling robust and reliable data transmission even in a noisy RF environment with interfering signals from WLAN, Bluetooth(r), WDCT systems and microwave ovens. This reference design is designed to meet the performance and cost requirements of wireless game controllers, but also addresses other wire-replacement applications in the consumer area, such as wireless audio links, interactive intelligent toys and remote controls. In addition to operating in the license-free 2.4 GHz ISM band, the reference design provides maximum flexibility since its two-chip solution allows the user to select the appropriate ATmega48/88/168 AVR according to the application firmware requirements. This reference design exhibits high performance with link ranges of up to 150m in free space and 30m indoors without an external power amplifier (PA) or low-noise amplifier (LNA). With an over-the-air data transmission rate of 1.152 Mbit/s, the reference design exhibits System manufacturing costs are reduced since a printed F antenna, balun and filter are included on the reference design. With a standard 2-layer circuit board, the design requires a minimal number of external components. Costs are further reduced since the AVR and Smart RF transceiver operate from a single crystal. The reference design includes complete Smart RF firmware with adaptive frequency-hopping scheme in C code, which is easily adaptable to any application. The ATmega48/88/168 AVR is supported with a full suite of programming and system development tools including C compilers, macro assemblers, programme debuggers/simulators and in-circuit emulators.

The ATR2406 part of the design is a single chip RF-transceiver. The QFN32 packaged IC includes an image rejection mixer, low IF filter, FM demodulator, RSSI, TX preamplifier, power-ramping generator for external power amplifier, integrated synthesiser, and a fully integrated VCO and TX filter. No mechanical adjustment is necessary in production and the device offers a clock recovery function on-chip. This high level of functional integration minimises external components and simplifies both design and manufacturing.