AS3990 Datasheet, PDF (1/2 Pages) ams AG – UHF RFID single chip reader EPC Class1 Gen2 compatible

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Data Sheet AS3977
UHF RFID single chip reader EPC Class1 Gen2 compatible
AS3990
Preliminary Information
General Description
The AS3990 UHF reader chip is an integrated
analogue front end and data framing system for a
900MHz RFID reader system. Built in programming
options make it suitable for a wide range of
applications in UHF RFID systems. Designed to
simplify the design and implementation of an EPC
Class 1Gen2 reader, this IC requires only a standard
8Bit microcontroller with minimal other components.
The AS3990 comprises the EPC Class 1- Gen2
protocol (ISO 18000-6c) with digital high speed logic
up to the framing level and supports the ISO 18000-
6a and ISO 18000-6b Protocol with direct data mode.
The Interface to the microcontroller can be either a 4
pin serial date Interface (SDI) or alternatively in case
of high data rates are necessary an eight Bit parallel.
The frame management will be done using a 12 Byte
FIFO in order to decrease processor workload and
ensure a smooth data stream and correct protocol
handling. All low level transmission codec’s and CRC
generation is done internally.
An on chip level shifter with a special supply pin can
be used to adapt microcontroller supply voltages in
the range of 1.8- 3.3V for optimized power usage. In
order to reduce the BOM, an integrated LDO with
driver strength of 20mA can be used to supply the
microcontroller. Additional regulators for the RF
section suppress disturbances and thus allow noisy
main supply.
Applications
• Barcode label printers
• Add-on module for handheld computers, PDA
• Point of sales
• Currency reader
• UHF RFID reader systems
• Hand-held UHF RFID readers
• Toll systems
• mobile phones
Key Features
• Fully compliant with ISO 18000 6a, 6b, 6c and
EPC Class 1- Gen2 protocol using external MCU
• EPC Class 1 -Gen2 framing support using low
cost 8 Bit microcontroller
• Direct data mode in the frequency range of 860 to
960 MHz enables propriety Protocol support
• Internal power amplifier with level controlled
20dBm for short range applications
• Modulator using ASK or PR-ASK modulation
• Adjustable ASK modulation index
• Automatic selection between I and Q Signal
ensuring no “communication holes”
• Built-in reception low-pass and high-pass filters
having selectable corner frequencies.
• On chip VCO and PLL covering complete RFID
frequency range and frequency hopping support
• Selectable receiver gain with AGC
• Supported link frequencies from 40 up to 640kHz
Package
• 64 pin QFN 9*9
A 20MHz crystal is used for the reference oscillator.
Using this reference, an additional programmable
glitch free clock output can be used to clock the
microcontroller thus saving costs and current. In
addition, by using the integrated power management
features modes power-down, standby and active it is
possible to shut down or reduce the microcontroller
clock and hence save additional power.
Revision 1.2, 20.09.2007
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