July 2003

1

MICRF008

MICRF008

Micrel

MICRF008

QwikRadio™ Sweep-Mode Receiver

General Description

The MICRF008 QwikRadio™ UHF receiver is a single-chip

OOK (on-off keyed) receiver IC designed for remote wireless

applications. This device is a true single-chip, “antenna-in,

data-out” device, and it is easy to implement. MICRF008

receiver requires very few peripheral passive components.

All tunings, RF and IF, are accomplished within the IC. Ease

of use and minimal parts count translate to cost savings and

shorter time to market. MICRF008 receiver offers a robust

and low-cost solution for high volume wireless applications.

The MICRF008 sweeps the internal local oscillator at rates

greater than the baseband data rate. This effectively broad-

ens the RF bandwidth of the receiver to a value equivalent to

conventional superregenerative receivers. This allows the

MICRF008 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.

Since all post-detection (demodulator) data filtering is pro-

vided on the MICRF008, no external IF filters are required.

One of the two internal filter bandwidths must be externally

selected based on data rate and code modulation format.

Typical Application

SEL0

VSS

REFOSC

ANT

CAGC

VDD

CTH

DO

C3

0.1µF

C1

1.8pF

L1

33nH

C4

2.2µF

U1

MICRF008BM

+5V

C2

4.7µF

Y1

3.36MHz

ANT1

1/8 Monopole

80mm

1

2

3

4

8

7

6

5

433.92MHz Receiver

Features

• Complete UHF receiver on a monolithic chip

• 300MHz to 440MHz frequency range

• Up to 4.8kbps data rate.

• Automatic tuning, no manual adjustment

• Very low RF antenna reradiation

• CMOS logic interface for standard ICs

• Low external part count

• Replaces superregenerative receivers design

• Manufacturability and same performance over the years

• Very small PCB area required

Applications

• Garage door and gate openers

• Security systems

• Remote appliances control

• Toys

• Fan and light control

Ordering Information

Part Number

Junction Temp. Range

Package

MICRF008BM

–40

°C to +85°C

8-Pin SOIC

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

QwikRadio™ is a trademark of Micrel.