MICRF004 Datasheet, PDF (1/16 Pages) Micrel Semiconductor – QwikRadio™ Low-Power VHF Receiver Advance Information

MICRF004/RF044
Micrel
MICRF004
QwikRadio™ Low-Power VHF Receiver
Advance Information
General Description
The MICRF004 QwikRadio™ VHF receiver is a single-chip
OOK (on-off keyed) receiver IC for remote wireless applica-
tions. This device is a true single-chip, “antenna-in, data-out”
device. All RF and IF tuning is accomplished automatically
within the IC which eliminates manual tuning production
costs and results in a highly reliable, extremely low-cost
solution for high-volume wireless applications.
The MICRF004 is extremely easy to apply, minimizing design
and production costs, and improving time to market. The
MICRF004 provides two fundamental modes of operation,
fixed and sweep.
In fixed mode, the device functions as a conventional super-
heterodyne receiver with an internal local oscillator operating
at a single frequency based on an external reference crystal
or clock. Fixed mode is for use with accurately-controlled
transmitters utilizing crystal or SAW (surface acoustic wave)
resonators.
In sweep mode, the MICRF004 sweeps the internal local
oscillator at rates greater than the baseband data rate. This
effectively broadens the RF bandwidth of the receiver to a
value equivalent to conventional superregenerative receiv-
ers. This allows the MICRF004 to operate with less expensive
LC transmitters without additional components or tuning,
even though the receiver topology is still superheterodyne. In
this mode the reference crystal can be replaced with a less
expensive ±0.5% ceramic resonator.
The MICRF004 features a shutdown control, which may be
used for duty-cycled operation, and a wake-up output, which
provides a logical indication of an incoming RF signal. These
features make the MICRF004 ideal for low- and ultra-low-
power applications, such as RKE (remote keyless entry) and
RFID (RF identification).
Since all post-detection (demodulator) data filtering is pro-
vided on the MICRF004, no external filters are required. One
of the four internal filter bandwidths must be externally
selected based on data rate and code modulation format.
Bandwidths range in binary steps, from 0.55kHz to 4.4kHz
(sweep mode) or 1.1kHz to 8.8kHz (fixed mode).
Features
• Complete VHF receiver on a monolithic chip
• 140MHz to 200MHz frequency range
• >200 meters typical range with monopole antenna
• 2.5kb/s sweep- and 10kb/s fixed-mode data rates
• Automatic tuning, no manual adjustment
• No filters or inductors required
• Low 240µA operating supply current at 150MHz
(10:1 duty cycle)
• Shutdown mode for >100:1 duty-cycle operation
• Wakeup for enabling decoders and microprocessors
• Very low RF antenna reradiation
• CMOS logic interface for standard ICs
• Extremely low external part count
Applications
• Automotive remote keyless entry
• Long range RF identification
• Remote fan and light control
• Garage door and gate openers
Ordering Information
Part Number Junction Temp. Range
Package
MICRF004BM
–40°C to +85°C
16-Lead SOP
MICRF004BN
–40°C to +85°C
16-Pin DIP
8-pin versions available. See “Custom 8-Pin Options,” following page.
Typical Application
+5V
0.047µF
MICRF004
4.85MHz
SSEELL00
SWEN (ceramic resonator)
VSSRF REFOSC
VSSRF
SEL1
ANT
CAGC
VDDRF WAKEB
4.7µF
VDDBB
CTH
NC
SHUT
DO
VSSBB
Data
Output
150MHz 1200b/s On-Off Keyed Receiver
QwikRadio is a trademark of Micrel, Inc.
Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 [phone] • fax + 1 [phone] • http://www.micrel.com
February 9, 2000
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MICRF004/RF044