MICRF113

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

General Description

The MICRF113 is a high performance, easy to use, single

chip ASK 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. MICRF113

has three strong attributes: power delivery, operating

voltage and operating temperature. In terms of power, the

MICRF113 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 MICRF113

operates from 1.8V to 3.6V. Many transmitter ICs in the

same frequency band stop operating below 2.0V. The

MICRF113 will work with most batteries to the end of their

useful limits. In terms of operating temperature, the

MICRF113 operates from -40°C to +85°C.

The MICRF113 is easy to use. It requires 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 MICRF113 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

MICRF113’s maximum ASK data rate is 10kbps

(Manchester Encoding).

The MICRF113 transmitter solution is ideal for industrial

and consumer applications where simplicity and form

factor are important.

Features

• Complete UHF transmitter

• Frequency range 300MHz to 450MHz

• Data rates up to 10kbps ASK

• Output Power to 10dBm

• Low external part count

• Low voltage operation (down to 1.8V)

• Operate with crystals or ceramic resonators

Applications

• Fan Controllers

• Remote Power Switches

• Multi-Media Remote Control

• Remote Sensor Data Links

• Infrared Transmitter Replacement

Ordering Information

Part Number

Temp. Range

Package

MICRF113YM6

–40°C to +85°C

SOT23-6

Typical Application

1

2

3

1

2

3

6

5

4

PAOUT

MICRF113

VSS

Vdd

C4

18pF

L2

82nH

(150nH)

L1

680nH

(470nH)

L3

PCB

ANTENNA

C2



4.7pF

(6.8pF)

C1

6.3V

C3



10pF

50V

C5

18pF

Y1 13.560MHz

(9.84375 MHz)

Vdd

ASK

XTLIN

XTLOUT

Vdd

DATA

Figure 1. MICRF113 ASK Key Fob Design for 315 MHz and 433.92 MHz

June 2008

M9999-060208

(408) 944-0800