描述

The AS3900 is a low power FSK transceiver ideal for battery-operated short range devices (SRD) applications in which a limited amount of data (data rate up to 210 kbit/s) need to be transferred. The device can be configured as transceiver, transmitter only or receiver only system and operates in one channel in the worldwide ISM band at 27 MHz.

The frequency of the external oscillator determines the operating frequency. Use of 27 MHz is in particular advantageous for communication in close proximity of the human body due to the low absorption of the signal by tissue because of the low specific absorption rate at 27 MHz. The device incorporates a serial digital interface (SDI), which enables bidirectional communication with external system components.

The integrated real-time-clock, sophisticated wake-up functionality, and link manager enable current efficient control of all communication events and eliminate the need for an expensive microcontroller.

The AS3900 supports data transfer in burst mode (bidirectional, controlled by link manager), semi-continuous (bidirectional, controlled by microcontroller) and continuous mode (unidirectional, controlled by microcontroller) and requires only a small number of external components.

主要特征

• FSK transceiver
• Operating frequency 27.12 MHz (ISM - band)
• Integrated real-time-clock (RTC) based on 32.768kHz XTAL
• FM deviation selectable (±106 kHz, ±53 kHz)
• Data transfer in burst mode and (semi-)continuous mode
• Data rate adjustable to 26.5, 53, 106, 212 kbit/s
• Low average current consumption in Tx and Rx mode
• Output power adjustable to 0, +5, +10 dBm
• Integrated OOK based wake-up system
• Link manager for control of star network with up to 8 clients
• Bidirectional serial digital interface (SDI)

Main Characteristics

• Operating temperature range -40ºC to +85ºC
• Operating supply voltage 2.2V to 3.6V (Functional down to 2.0V)
• Rx current consumption 3.8 mA (typ.)
• Tx current consumption 4.9 mA@0dBm, 7.6 mA @10dBm
• Maximum output power 10 dBm (delivered to matching network and antenna)
• Receiver sensitivity –85 dBm @ 105 kbit/s
• Polling mode average current consumption typ. 2.5μA
• Power down current consumption max. 700nA
• Typ. communication range using small antenna 1.2m@0dBm, 2.5m@10dBm
• QFN 28 pin (5x5) package

Additional Features

• Reliable pairing and synchronization of master and clients
• Automatic 16 bit CRC computation in burst mode
• Auto-acknowledgement and re-transmit
• Programmable timers to assign variable communication cycle times
• Reliable system start due to internal POR
• Programmable microcontroller clock frequency
• Separate interrupt request line
• Battery level detector
• Digital RSSI value accessible in register
• User programmable Identification with OTP memory (24 bits)

产品应用

The AS3900 is ideal for reliable low-power short-range data exchange, data transfer among devices in close proximity of human body (Body Area Networks), simple control networks (home, industry), and interactive remote controls. A typical application can be designed in combination with a microcontroller, an antenna and a few additional passive components.

Block diagram for AS3900 27MHz Star Network Transceiver