[TechView: Wireless]
Single-Chip ZigBee Radio Kicks Up The Data Rate While Boosting Battery Life
Louis E. Frenzel
ED Online ID #15426
May 10, 2007
Copyright © 2006 Penton Media, Inc., All rights reserved.
Printing of this document is for personal use only.
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More and more, designers are
using the ZigBee short-range
wireless technology to monitor remote sensors and transmit simple control messages in their industrial, building
automation, and home applications. Freescale Semiconductor's MC1322x Platform in Package (PiP) not only makes it easier to implement ZigBee in these and other applications, it also offers ultra-low power consumption.
ZigBee is an enhancement to the IEEE 802.15.4
personal-area networking (PAN) standard, which permits transceiver nodes to link with many adjacent nodes to form mesh networks. The nodes can send and receive
messages as they go about their normal
function, but they also can act as
repeaters passing messages from one
node to another. This quality allows the
overall range of the networks to be
extended while improving overall network reliability because of the multiple
paths available in case of the failure of
one node.
Based on the IEEE's 802.15.4 standard and a supplementary standard
from the ZigBee Alliance, most ZigBee
units operate in 16 channels of the 2.4GHz industrial, scientific, and medical
(ISM) band and can transmit up to 250
kbits/s. With the ZigBee-compliant
stack, the radios work in a mesh configuration that extends the network's range
and improves reliability because of the
multiple paths available.
The single-chip MC1322x includes a
fully compliant 802.15.4 transceiver and
a 32-bit microcontroller (see the figure).
The on-chip ROM contains the various
device drivers and the 802.15.4 media-access controller (MAC). The chip also
includes RAM and flash memory of various sizes. All of the RF antenna matching components, including a balun, are
on chip.
The only required external parts are
the antenna itself and a crystal. The
chips in this family also boast better than
–95-dBm receiver sensitivity. They feature a hardware MAC accelerator and
topology support for peer-to-peer,
star, and mesh networking as
well. Operating voltage
ranges from 1.8 to 3.6 V
with less than 20-mA
drain, making them ideal
for coin-cell power.
The proprietary TurboLink technology gives the chip an alternate 2-Mbit/s data rate.
With it, the MC1322x can
support new typically nonZigBee applications such
as voice, wireless headsets, compressed audio,
and large data transfers like those in some
healthcare patient monitoring systems.
The chip has 64 general-purpose I/O
(GPIO) lines, two 12-bit analog-to-digital
converters, and four timers. Its interfaces
include pulse-width modulation (PWM),
serial peripheral interface (SPI), serial
communications interface (SCI), and I2C.
The chip comes in a 9.5- by 9.5- by 1.2-mm land-grid array (LGA) package
and a 7- by 7- by 1-mm quad flat no-lead
(QFN) package. Pricing is typically $5.50
in 10,000-unit lots. Samples will be available to key OEM customers this month
with general sampling scheduled for
December.
The MC1322x's BeeKit development
software makes it easier for customers to
create ZigBee applications. Its easy to
use interface and framework help users
configure parameters for their applications. It includes Freescale's BeeStack, a
ZigBee Alliance-compliant protocol stack,
plus pre-configured ZigBee application
samples and templates. Also, it includes
the ZigBee Alliance's next-generation
home-control protocol stack and Home
Automation profile.
Freescale Semiconductor Inc.
www.freescale.com/zigbee
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