The AS3940 is a highly integrated low power FSK transceiver for wireless communication in the worldwide 2.4 GHz ISM band. It supports data transfer in burst mode and streaming mode at data rates up to 2 Mbit/s.

All communication with a MCU and all configuration of the transceiver can be done using a bidirectional 4 pin serial data interface (SDI). The integrated timers and link manager enable very low average current consumption in operation and standby and help to reduce overall system cost by eliminating the need for a complex microcontroller (MCU). Optimum MCU clock frequency can be obtained from a programmable glitch-free clock output derived from the 16 MHz reference crystal oscillator.

The integrated link manager controls all power management modes, like power-down, standby, sleep, wakeup, and data mode, which enable to save power. The link manager handles all data and frame management in a star network (one master and up to 8 clients) using four separate 256-bit data buffers; two for RX and two for TX. This decreases MCU workload and ensures a smooth data transfer and correct protocol handling. All low level transmission codec and CRC generation is done internally. Microcontroller controlled data transfer (MCDT) mode enables support of proprietary protocols.
Excellent blocking and sensitivity, pseudorandom allocation of communication time slots and the adaptive channel switching enable reliable data transmission and high resistance to interferers like WLAN or Bluetooth.

The high level of integration eliminates the need for external components like battery monitoring circuitry, additional high frequency crystal, and power-on-reset circuitry.

The product is available in a QFN 32 pin (5mm x 5mm) package.