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MICRF405
290MHz – 980MHz ISM Band
ASK / FSK Transmitter
MicroLead Frame and MLF are registered trademarks of Amkor Technologies
RadioWire 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
April 2006
M9999-041906
(408) 955-1690
General Description
The MICRF405 is a 290MHz-980MHz RF transmitter
IC designed for unlicensed ISM band operations. It's
designed to work in the North American 315MHz
and 915MHz bands as well as the European
433MHz and 868MHz bands. The device is fully
FCC Part 15.247 and EN300-220-compliant.
The transmitter consists of a FSK/ASK modulator,
PLL frequency synthesizer and a power amplifier.
The frequency synthesizer consists of a voltage-
controlled oscillator (VCO), a crystal oscillator, dual
modulus prescaler, programmable frequency
dividers and a phase-detector. The loop-filter can be
internal or external. The output power of the power
amplifier can be programmed to eight levels. A lock
detect circuit detects when the PLL is in lock.
In FSK mode, the user can select between three
different modulation types allowing a data rate up to
200kbps. When selecting FSK modulation applied
with dividers, the MICRF405 is switching between to
sets of register values (M0,N0,A0:"0" and M1,N1
and A1:"1"). The second modulation type is closed
loop VCO modulation using the internal modulator
that applies the modulated data to the VCO. The
third FSK modulation type is Open loop VCO
modulation.
In ASK modulation, the user can select between two
modulation types, with or without spreading. In both
modes the modulation depth is programmable.
RadioWire
®
Features
•
FSK/ASK transmitter
•
Frequency programmable
•
ASK modulation depth programmable
•
High efficiency power amplifier
•
Programmable output power
•
Power down function
•
MCU reference clock
•
Base band package engine
•
TX buffer
•
No external tuning circuitry
Applications
•
Meter reading
•
Automotive
•
Smart Home
•
Remote control systems
•
Residential Automation
•
Wireless security system