Micrel Inc.

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

MICRF002 / 022

QwikRadio

Preliminary Information

General Description

The MICRF002, an enhanced version of the MICRF001 and MICRF011,

is a single chip OOK (ON-OFF Keyed) Receiver IC for remote wireless

applications, employing Micrel’s latest QwikRadio

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

MICRF002 is a true single-chip radio receiver, it is extremely easy to

apply, minimizing design and production costs, and improving time to

market.

The MICRF002 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 MICRF002 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 MICRF002 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.

The

MICRF002

provides

two

feature

enhancements

over

the

MICRF001/011, (1) a Shutdown Mode, which may be used for duty-

cycle operation, and (2) a “Wakeup” function, which provides a logical

indication of an incoming RF signal.

These features make the

MICRF002 ideal for low and ultra-low power applications, such as RKE

and RFID.

All post-detection (demodulator) data filtering is provided on the

MICRF002, 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

(10:1 Duty Cycle)

of 100:1

Microprocessors

microprocessor ICs

Applications

Typical Operating Circuit

385.5 MHz, 1200 bps OOK RECEIVER