General Description
The AS3901 is a low power FSK/ (ASK) transmitter intended for the European 433 MHz and the US 315 MHz ISM band application. It uses a PLL stabilized oscillator which avoids frequency pulling by approaching the antenna with objects as it occurs at SAW resonator based transmitters.

Key Features
· 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.
· Supports FSK (data rates 0… 32 kb/s) or ASK modulation (data rates 0… 20kb/s)
· No data synchronization for FSK or ASK needed.
· Supports clock and reset signals for the external µC.
· Supports different power down modes, one without any running XTAL oscillator.
· Wide supply range between 2.7 V to 5 V.
· Only one XTAL and very few external elements required.
· Wide operating temperature range from –40 C to +85 C.
· Low TX current, typical 7 mA

Applications
· Short range radio data transmission.
· Remote keyless entry systems.
· Security applications and alarm systems.
· Domestic and consumer remote control units.
· Remote metering.
· Low power telemetry.