MICRF112

QwikRadio is a registered trademark of Micrel, Inc.

Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com

December 2011

M9999-120911

(408) 944-0800

General Description

The MICRF112 is a high performance, easy to use, single

chip ASK / FSK Transmitter IC for remote wireless

applications in the 300 to 450MHz frequency band. This

transmitter IC is a true “data-in, antenna-out” monolithic

device.

MICRF112 is high performance in three areas: power

delivery, operating voltage, and operating temperature. In

terms of power, the MICRF112 is capable of delivering +10

dBm into a 50Ω load. This power level enables a small

form factor transmitter (lossy antenna) such as a key fob

transmitter to operate near the maximum limit of

transmission regulations. In terms of operating voltage,

the MICRF112 operates from 3.6V to 1.8V.

Many

transmitter ICs in the same frequency band stop operating

below 2.0V. The MICRF112 will work with most batteries

to the end of their useful limits. In terms of operating

temperature, the MICRF112 operates from -40°C to

+125°C. This wide operating temperature range makes

MICRF112 an ideal candidate for the demanding

applications such as a tire pressure monitoring system.

The MICRF112 is easy to use.

One only needs a

reference frequency (RF carrier frequency divided by 32

times) generated from a crystal with a few additional

external parts to create a complete versatile transmitter.

The MICRF112 operates with ASK/OOK (Amplitude Shift

Keying/On-Off Keyed) UHF receiver types from wide-band

super-regenerative

radios

to

narrow-band,

high

performance

super-heterodyne

receivers.

The

MICRF112’s maximum ASK data rate is 50kbps

(Manchester Encoding). It operates with FSK receivers as

well. The chip is designed to support narrow band FSK

(Frequency Shift Modulation) by switching an external

capacitor in parallel with the reference crystal. The

MICRF112’s maximum FSK data rate is 10kbps.

Features

 Complete UHF transmitter

 Frequency range 300MHz to 450MHz

 Data rates up to 50kbps ASK, 10kbps FSK

 Output Power to 10dBm

 Low external part count

 Low standby current <1µA

 Low voltage operation (down to 1.8V)

 Operate with crystals or ceramic resonators

Applications

 Remote Keyless Entry Systems (RKE)

 Remote Control (STB, HVAC and Appliances)

 Garage Door Opener Transmitters

 Remote Sensor Data Links

 Infrared Transmitter Replacement

 Tire Pressure Monitor System (TPMS)

Ordering Information

Part Number

Temp. Range

Package

MICRF112YMM10

–40°C to +125°C

10-Pin MSOP