Data Sheet AS3940 2.4 GHz Low Power Multi-Channel FSK Transceiver 1 General Description 2 Key Features Fully integrated FSK transceiver The AS3940 is a highly integrated low power FSK transceiver for wireless communication in the worldwide 2.4 GHz ISM band. It Operating frequency 2405 to 2480 MHz supports data transfer in burst mode and streaming mode at data Minimum channel spacing 1MHz rates up to 2 Mbit/s. Data rates in burst mode 250, 1000, 2000 kbps All communication with a MCU and all configuration of the Net data rate in streaming mode up to 1000 kbps transceiver can be done using a bidirectional 4 pin serial data Sensitivity of -100dBm 250kbps, -95.5dBm 1000kbps, and interface (SDI). -92.5dBm 2000kbps The integrated timers and link manager enable very low average current consumption in operation and standby and help to reduce Excellent adjacent channel rejection and blocking performance overall system cost by eliminating the need for a complex Package synchronized digital RSSI microcontroller (MCU). Integrated real-time-clock (RTC), 32 kHz XTAL oscillator / Optimum MCU clock frequency can be obtained from a calibrated 6.25 kHz derived from a RCO programmable glitch-free clock output derived from the 16 MHz Glitch-free CMOS compatible reference clock output 8/4/2/1 reference crystal oscillator. MHz or 6.25 kHz The integrated link manager controls all power management modes, Output power programmable in 3dB steps (-24 dBm to 0 dBm) like power-down, standby, sleep, wakeup, and data mode, which enable to save power. Integrated Gaussian filter, PLL and loop filter The link manager handles all data and frame management in a star 4 separate 256-bit user data buffers (2 x RX, 2 x TX) network (one master and up to 8 clients) using four separate 256-bit Power on reset (POR, NPOR) for reliable system start data buffers two for RX and two for TX. This decreases MCU Battery voltage detection workload and ensures a smooth data transfer and correct protocol Link manager for reliable control of star network (up to 8 clients) handling. All low level transmission codec and CRC generation is done internally. Microcontroller controlled data transfer (MCDT) Device ID recognition and 16-bit CRC computation mode enables support of proprietary protocols. Pairing and automatic (re-)synchronization Excellent blocking and sensitivity, pseudorandom allocation of Power-optimized wakeup modes communication time slots and the adaptive channel switching enable Programmable auto-acknowledgement and re-transmit reliable data transmission and high resistance to interferers like Adaptive channel switching / support of frequency hopping WLAN or Bluetooth. Programmable timers to define time slots for communication The high level of integration eliminates the need for external components like battery monitoring circuitry, additional high Pseudorandom allocation of time slots frequency crystal, and power-on-reset circuitry. The product is available in a QFN 32 pin (5mm x 5mm) package. 3 Applications The AS3940 is ideal for low-power short range devices, body area networks (health, fitness), simple control networks (industry, home), and interactive remote controls. www.austriamicrosystems.com/AS3940 Revision 1.0 1 - 71EXT RESET MCCLK NC NPOR POR D REG CTRL VDD SYNTH REXTP AS3940 Data Sheet - Applications Figure 1. Block diagram AS3940 Analog Digital CLK XREF POR 16MHz XTAL VDD RX MIX Regulator Regulator cleaning INT XREF RCO TX D 32kHz XTAL 6.25kHz A (Optional) VDD RF1 RTC 16MHz Digital Modem PA LO RFCM1 XTAL3 16MHz CRC Code/Decode D A RFINP RSSI XTAL4 RX D AGC A Link Manager RFINN CS Data 16MHz Timers 8x Time code Buffers LNA LO Timeout RFCM2 4x256-bit SCLK 16MHz D PRBS AGC Generator A VDD RF2 MISO Battery Level Detector Synthesizer SDI REXTN MOSI www.austriamicrosystems.com/AS3940 Revision 1.0 2 - 71 VDD IF RTX A REG OUT A REG IN D REG OUT XTAL2 XTAL1 VDD CLK CE