Micrel Inc.

• 1849 Fortune Drive San Jose, Ca 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com

MICRF011

QwikRadio

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

“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

antenna

and microprocessor ICs

Applications

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