General Description
The IC is a low power consumption single chip FSK/ASK Transceiver for half duplex low datarate communication in the 915MHz band. The IC offers a very high level of integration and needs only a few external components. It contains a highly efficient power amplifier, a low noise amplifier (LNA) with AGC, a double balanced mixer, a complex direct conversion stage, I/Q limiters with RSSI generation, an FSK demodulator, a fully integrated VCO and PLL synthesizer, a tuneable crystal oscillator, an onboard data filter, a data comparator (slicer), positive and negative peak detectors, a data rate detection circuit and a 2/3-wire bus interface. Additionally there is a power down feature to save battery power.

FEATUREs
– Low supply current (Is = 9mA typ. receive, Is = 13mA typ. transmit mode)
– Supply voltage range 2.1 - 5.5V
– Power down mode with very low supply current consumption
– FSK and ASK modulation and demodulation capability
– Fully integrated VCO and PLL synthesizer and loop filter on-chip with on chip crystal oscillator tuning
– I2C/3-wire µController Interface
– On-chip low pass channel select filter and data filter with tuneable bandwidth
– Data slicer with self-adjusting threshold and 2 peak detectors
– FSK sensitivity < -109dBm,
   ASK sensitivity < -109dBm
– Transmit power up to +13dBm
– Self-polling logic with ultra fast data rate detection

APPLICATION
– Low Bitrate Communication Systems
– Keyless Entry Systems
– Remote Control Systems
– Alarm Systems
– Telemetry Systems
– Electronic Metering
– Home Automation Systems