ISM 433 MHz ASK Transmitter – Preliminary Data Sheet

AS3902

Rev. A7, December 2000

Page 2 of 14

Key Feature s

• Supports the European 433 MHz ISM band.

• No frequency pulling by (antenna) load variation due to PLL synthesizer.

• Designed to be conform to EN 300 220-1 requirements.

• ASK data rate range from 0 to 32 kbit/s.

• Supports clock and reset signals for the external µC. Therefore no separate µC XTAL is

required.

• Supports total shut down mode without any running XTAL oscillator.

• Typically 2 external resistors and 3 capacitors required.

• FSK operation by XTAL pulling possible.

• 315 MHz US ISM band application possible.

• Wide supply range between 2.7 V to 5 V.

• Low TX current, typical 8 mA @ transmitting a High (“H“), 1 mA @ transmitting a Low (“L“).

• Wide operating temperature range from –40 °C to +85 °C.

General Descriptio n

The AS3902 is a single channel low power 433 MHz ASK transmitter. It uses a fully integrated

PLL stabilized RF-oscillator which avoids frequency pulling by approaching the antenna with

objects as it occurs at SAW resonator based transmitters. ASK modulation is performed by

switching the transmitter on and off by an applied data stream.

The AS3902 contains a bi-directional three line micro-controller (µC) interface to support the

µC with a clock and a reset signal and to operate the highly efficient power up/down manage-

ment (including clock-free total shut-down) of the AS3902 by the µC.

As external components the AS3902 need only a reference XTAL, three capacitors and up to

two resistors.

Application s

• Short range radio data transmission.

• Remote keyless entry systems.

• Domestic and consumer remote control units.

• Cordless alarm systems.

• Remote metering.

• Low power telemetry.