Dat a Sh eet AS3990/AS3991 UHF RFID Single Chip Reader EPC Class1 Gen2 Compatible 1 General Description 2 Key Features ISO18000-6C (EPC Gen2) full protocol support The AS3990/AS3991 UHF reader chip is an integrated analog front end and protocol handling systems for a ISO18000-6A,B compatibility in direct mode ISO18000-6C 900MHz RFID reader system. Integrated low level transmission coding Equipped with built-in programming options, the device Integrated low level decoders is suitable for a wide range of UHF RFID applications. The AS3990/AS3991 includes improved on-board VCO Integrated data framing and internal PA. Integrated CRC checking The reader configuration is achieved by selecting the Parallel 8-bit or serial 4-pin SPI interface to MCU desired protocol in control registers. Direct access to all using 24 bytes FIFO control registers allows fine tuning of different reader parameters. Voltage range for communication to MCU between 1.8V and 5.5V Parallel or serial interface can be selected for communication between the host system (MCU) and the Selectable clock output for MCU reader IC. When hardware coders and decoders are Integrated supply voltage regulator (20mA), which used for transmission and reception, data is transferred can be used to supply MCU and other external via 24 bytes FIFO register. circuitry In case of direct transmission or reception, coders and Integrated supply voltage regulator for the RF output decoders are bypassed and the host system can service stage, providing rejection to supply noise the analog front end in real time. Internal power amplifier (20dBm) for short range The transmitter generates 20dBm output power into 50 applications load and is capable of ASK or PR-ASK modulation. The integrated supply voltage regulators ensure supply Modulator using ASK or PR-ASK modulation rejection of the complete reader system. Adjustable ASK modulation index The transmission system comprises low level data AM & PM demodulation ensuring no coding. Automatic generation of FrameSync, Preamble, communication holes with automatic I/Q selection and CRC is supported. Built-in reception low-pass and high-pass filters The receiver system allows AM and PM demodulation. having selectable corner frequencies The receiver also comprises automatic gain control option (patent pending) and selectable gain and signal Selectable reception gain bandwidth to cover a range of input link frequency and Reception automatic gain control bit rate options. AD converter for measuring TX power using The signal strength of AM and PM modulation is external RF power detector measured and can be accessed in RSSI register. DA converter for controlling external power amplifier The receiver output is selectable between digitized sub- carrier signal and any of integrated sub-carrier Frequency hopping support decoders. Selected decoders deliver bit stream and data On-board VCO and PLL covering complete RFID clock as outputs. frequency range 840MHz to 960MHz The receiver system also comprises framing system. Oscillator using 20MHz crystal This system performs the CRC check and organizes the data in bytes. Framed data is accessible to the host Power down, standby and active mode system through a 24 byte FIFO register. Can be powered by USB with no need for step To support external MCU and other circuitry a 3.3V conversion regulated supply and clock outputs are available. The regulated supply has 20mA current capability. 3 Applications The AS3990/AS3991 is available in a 64-pin QFN (9mm The device is an ideal solution for UHF RFID reader x 9mm), ensuring the smallest possible footprint. systems and hand-held UHF RFID readers. www.austriamicrosystems.com Revision 3.81 1 - 51AS3990/AS3991 Data Sheet - Applications Figure 1. Block Diagram 4xC 2xC 64 213 5 53 52 13 15 16 17 38 VDD D OAD 31 VDD RF 18 30 OAD 2 VDD B 19 AS3990/ Supply ADC 58 Regulators AGD 54 & DAC 4 AS3991 59 VDD A 7xC References 63 VDDLF 61 VOSC Gain IQ Down VDD RFP Filter 34 Conversion Digitizer Mixer MIX INP 7 MIX INN 9 51 VDD IO Digitizer MIXS IN 10 41 IO0 42 IO1 AFE 43 IO2 RFOUTN 1 27 RF Out 44 IO3 RSSI RFOUTN 2 28 45 IO4 RFOUTP 1 20 Micro 46 IO5 RFOUTP 2 21 controller 47 IO6 RFONX 32 Directional 48 IO7 RFOPX 33 unit EPC Gen2 Protocol 56 50 CLK EXT IN Handling 39 EN 36 GEN-2 40 IRQ OCSI 49 CLSYS 24 Frame Gen 37 OSCO Byte FIFO 60 CRC VCO 62 CP 6 8 11 12 14 22 23 24 25 26 29 35 55 57 65 www.austriamicrosystems.com Revision 3.81 2 - 51 VSS COMP A VSS COMP B VSN MIX COMN A Oscillator & Timing CBIB System COMN B CBV5 VDD 5LFI VSN 1 VSN 2 CD1 VSN 3 CD2 VSN 4 VSN 5 VDD MIX VSN D VSN RFP VDD TXPAB VSN A VSN CP EXP PAD VEXT VEXT2 MCU Interface