ZigBee modules tap ARM Cortex-M3 - 11 November 2009 - CST Electronics

ZigBee modules tap ARM Cortex-M3
11 November 2009, Telecoms, Datacoms, Wireless, IoT

The ETRX3 series is the third generation of ZigBee modules from Telegesis and features the EM357 and EM351 – the latest ARM Cortex-M3 systems-on-chip from Ember.

ETRX3 series modules have a footprint of just 19 x 25 mm for both standard and PA/LNA versions, which represents a 40% reduction in size compared to the ETRX2 module. They are available with either an onboard antennae or a Hirose U.FL connector to allow connection of external antennas. A link budget of 105 dB on the standard ETRX3 module gives excellent performance and RF power can be further boosted by use of the ETRX3-LR which adds an extra LNA and PA, boosting the link budget to 123 dB.

The ETRX3 series are low-power ZigBee modules integrating a 2,4 GHz, IEEE 802.15.4 compliant transceiver with up to 192 KB of Flash, 12 KB of RAM and many advanced peripherals. The EM357 and EM351 utilise an efficient architecture that exceeds the dynamic range requirements imposed by the IEEE 802.15.4-2003 standard by over 15 dB. The integrated receive channel filtering allows for robust co-existence with other communication standards in the 2,4 GHz spectrum, such as IEEE 802.11 and Bluetooth.

The ARM Cortex M3 microprocessor is optimised for high performance, low power consumption, and efficient memory utilisation, making it well suited for use in ZigBee applications. To maintain the strict timing requirements imposed by the ZigBee and IEEE 802.15.4-2003 standards, the EM357and EM351 integrate a number of MAC functions into the hardware, handling automatic ACK transmission and reception, automatic backoff delay and clear channel assessment for transmission, as well as automatic filtering of received packets.

ETRX3 series modules work from a 2,1 to 3,6 V supply and active power consumption is reduced by over 20% compared to the ETRX2. In deep sleep mode, current consumption is reduced to 800 nA and further reduced to 400 nA when the self wakeup feature is not enabled. ETRX3 series modules features all the software present on other Telegesis ZigBee modules, such as the Telegesis AT command set, which allows the designer to use the functionality of the EmberZNet stack without the need for complex embedded code. Development is also eased by the addition of an integrated JTAG and debugging interface.

For more information contact Christo Keyser, CST Electronics, +27 (0)11 608 0070, sales@cstelectronics.co.za, www.cstelectronics.co.za