MICRF221_15 Datasheet, PDF (1/26 Pages) Micrel Semiconductor – 3.3V, QwikRadio® 850 MHz to 950 MHz Receiver

MICRF221
3.3V, QwikRadio^® 850 MHz to 950 MHz
Receiver
General Description
The MICRF221 is a third generation QwikRadio^®
receiver, offering all the benefits of Micrel's earlier
QwikRadio^® products with significant improvements,
including: enhanced sensitivity, automatic duty-cycle
feature and RSSI output.
The MICRF221 is a super-heterodyne receiver,
designed for OOK and ASK modulation. The down-
conversion mixer also provides image rejection.
The MICRF221 receiver provides a SLEEP Mode for
duty-cycle operation and an enhanced, customer
programmable "WAKE" function. These features are
further combined into a wholly integrated "self-polling"
scheme that is ideal for low and ultra-low power
applications, such as RKE and RFID
All post-detection data filtering is provided on the
MICRF221 receiver. Any one of four filter bandwidths
may be selected externally by the user in binary steps,
from 1.25kHz to 10kHz. The user needs only to program
the device with a set of easily determined values based
on data rate, code modulation format, and desired duty-
cycle operation.
Datasheets and support documentation are available on
Micrel’s website at: www.micrel.com.
Typical Application
Features
• Complete receiver on a chip
• -109dBm sensitivity, 1kbps, and BER 10^-2
• Image rejection mixer
• 850MHz to 950MHz frequency range
• Low power, 9mA @ 868MHz, continuous on
• Data rates to 10kbps (Manchester Encoded)
• Auto polling (sleep mode, current < 0.1 mA)
• Analog RSSI output
• Programmable “low sensitivity” mode
• No IF filter required
• Excellent selectivity and noise rejection
• Low external part count
• Additional functions programmed through serial
interface
Figure 1: MICRF221 Receiver 915.0 MHz, 1kHz Baud Rate Example
QwikRadio is a registered trademark of Micrel, Inc.
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel [phone] • fax + 1 [phone] • http://www.micrel.com
August 12, 2015
Revision 2.0