1424F–RKE–12/03
Features
RF Frequency Range of 264–456 MHz
6 dBm RF Output into Matched Antenna
RF Output Power Adjustable over 36 dB with 1 dB Resolution
Phase-locked Loop (PLL) Based Frequency Synthesizer
Supports OOK Modulation
Data Bandwidth of Up to 10 Kbps Manchester
2-volt Operation
8-bit AVR

RISC Microcontroller Core
Minimal External Components
Space-saving 20-lead TSSOP
2 KB (1K x 16) of Flash Program Memory
128 Bytes of EEPROM
128 Bytes of SRAM
In-system Programmable Data and Program Memory
Six I/Os (Serial I/F, LED Drive Outputs, Button Input Interrupts)
Low Battery Detect and Brown-out Protection
Software Fine-tuning of VCO Tank Circuit
Applications
Remote Keyless Entry (RKE) Transmitters
Wireless Security Systems
Home Applicance Control (Lighting Control, Ceiling Fans)
Radio Remote Control (Hobby, Toys)
Garage Door Openers
Wireless PC Peripherals (Keyboard, Mouse)
Telemetry (Tire Pressure, Utility Meter, Asset Tracking)
Description
The Atmel AT86RF401 Smart RF Microtransmitter is a highly integrated, low-cost RF
transmitter, combined with an AVR RISC microcontroller. It requires only a crystal, a
single LiMnO
2
coin cell (CR2032 or similar), three capacitors, an inductor and a tuned-
loop antenna to implement a complete on-off keyed (OOF) wireless RF data
transmitter.
Figure 1. Block Diagram
PHASE
DETECTOR
OSCILLATOR
LOOP
FILTER
VCO
PRESCALER
÷ 24
RF
AMP
LOOP FIL
CLOCK
RESET
WATCHDOG
LOW-VOLTAGE DETECT
BROWN-OUT PROTECT
AVR

RISC µC
2 KB Flash Program Memory
128 Bytes EEPROM Data Memory
L1 L2
DATA GAIN
TRIM
POWER
SUPPLY
SUPERVISOR
XTAL/CLK
XTALB
AVDD
AGND
ANT
ANTB
B+
D
VDD
DGND
IO5 IO4 IO3
SCK/IO2 SDO/IO1
SDI/IO0
RESETB
Smart RF
Wireless Data
Microtransmitter
AT86RF401