MICRF221 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, Figure 1, 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 1.25 kHz to 10 kHz. 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.
Typical Application
Features
• Complete Receiver on a Chip
• -109dBm sensitivity, 1 kbps and BER 10E-02
• Image Rejection Mixer
• 850 MHz to 950 MHz frequency range
• Low Power, 9mA @ 868 MHz, 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
Ordering Information
Part Number
Temperature Range
MICRF221AYQS
–40° to +105°C
Package
16-Pin QSOP
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
October 2008
M9999-100108
[phone]