The EM-250 system-on-a-chip (SoC) packs a host of features that fit ZigBee applications. Developed by Ember Corp., this radio includes a 2.4-GHz transceiver, the low-power XAP2 16-bit processor, 128 kbytes of flash memory, 5 kbytes of RAM, and the ZigBee stack software. It also fully complies with IEEE 802.15.4.
Derived from work done at Cambridge Consultants, this fourth-generation chip doubles the range of previous Ember devices and competitive products. In fact, Ember chairman and Ethernet inventor Bob Metcalfe challenges designers to compare the EM-250 with competitive chips!
The EM-250 offers a ?94-dBm receive sensitivity and transmit power to +4 dBm. Its adjacent channel rejection is less than 30 dB, and its alternative channel rejection is less than 40 dB. Operating from a 2.1- to 3.6-V supply, it only requires a 24-MHz crystal and the LC network for antenna matching. It comes in a 7- by 7-mm, 48-pin quad leadless package.
An alternate version, the EM-260, is configured so designers can use a microcontroller of their own choosing to run their application. It incorporates a serial peripheral interface and acts as the slave to the customer's microcontroller master. The EM-260 also supports a standard UART interface. It comes in a 6- by 6-mm, 40-pin quad-flat-nonleaded chip.
A development kit with all the latest software and hardware is available as well (see the figure).