MICRF011
QwikRadio
tm
Receiver/Data Demodulator
Preliminary Information
General Description
The MICRF011, an enhanced version of the MICRF001, is a single chip
OOK (ON-OFF Keyed) Receiver IC for remote wireless applications,
employing Micrel’s latest QwikRadio
tm
technology. This device is a true
“antenna-in, data-out” monolithic device. All RF and IF tuning is
accomplished automatically within the IC, which eliminates manual
tuning and reduces production costs. Receiver functions are completely
integrated. The result is a highly reliable yet extremely low cost solution
for high volume wireless applications. Because the MICRF011 is a true
single-chip radio receiver, it is extremely easy to apply, minimizing design
and production costs, and improving time to market.
The MICRF011 is a functional and pin equivalent upgrade to the
MICRF001, providing improved range, lower power consumption, and
higher data rate support when in FIXED mode.
The MICRF011 provides two fundamental modes of operation, FIXED
and SWP. In FIXED mode, the device functions like a conventional
superheterodyne receiver, with an (internal) local oscillator fixed at a
single frequency based on an external reference crystal or clock. As with
any conventional superheterodyne receiver, the
transmit
frequency must
be accurately controlled, generally with a crystal or SAW (Surface
Acoustic Wave) resonator.
In SWP mode, the MICRF011 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
super-regenerative receivers. Thus the MICRF011 can 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.
All post-detection (demodulator) data filtering is provided on the
MICRF011, so no external filters need to be designed. Any one of four
filter bandwidths may be selected externally by the user. Bandwidths
range in binary steps, from 0.625kHz to 5kHz (SWP mode) or 1.25kHz to
10kHz (FIXED mode). The user only needs to program the appropriate
filter selection based on data rate and code modulation format.
Features
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Complete UHF receiver on a monolithic chip
Frequency range 300 to 440 MHz
Typical range over
200
meters with monopole
antenna
Data rates to
2.5kbps
(SWP),
10kbps
(FIXED)
Automatic tuning, no manual adjustment
No Filters or Inductors required
Low Operating Supply Current—2.4
mA
at 315MHz
Fully pin compatible with MICRF001
Very low RF re-radiation at the antenna
Direct CMOS logic interface to standard decoder
and microprocessor ICs
Extremely low external part count
Applications
Garage Door/Gate Openers
Security Systems
Remote Fan/Light Control
IMPORTANT: Items in bold type represent changes from
the MICRF001 specification. Differences between the
MICRF001 and -011 are identified in table 2, together with
design considerations for using the -011 in present
MICRF001 designs.
Typical Operating Circuit
385.5 MHz, 1200 bps OOK RECEIVER
Micrel Inc.
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1849 Fortune Drive San Jose, Ca 95131
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USA
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tel + 1 (408) 944-0800
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fax + 1 (408) 944-0970
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http://www.micrel.com
MICREL [ MICREL SEMICONDUCTOR ]
