Easy RFID with high-integration reader-chip

The AS3990/91 Ultra-High Frequency (UHF) reader chip is an integrated analogue front-end and data-framing system for a 900MHz Radio-Frequency Identification (RFID) reader system.

With its built-in programming options the unit is suitable for a wide range of applications in UHF RFID systems and requires only a standard 8-bit microcontroller with minimal additional components.

The AS3990/91 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 protocols with direct-data mode.

The connection to the microcontroller can be either a 4-pin Serial Data Interface (SDI) or alternatively, for high data rates, an 8-bit parallel interface.

Frame management is performed using a 24-byte FIFO, which decreases processor workload as well as ensuring a smooth data-stream and correct protocol handling. All low-level transmission codecs and CRC generation is done internally. Additional regulators for the RF section suppress disturbances and thus can operate with noisy mains supply.

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. This saves cost and also reduces overall current draw. In addition, by using the integrated power-management modes of power-down, standby and active, it is possible to shut down or reduce the MCU clock to save additional power.

The transmitter generates 20dBm output power into a 50Ω load and is capable of ASK-DSB or PR-ASK modulation. The receiver system enables AM and PM demodulation. The receiver also offers an Automatic Gain Control (AGC) option as well as selectable gain and signal-bandwidth to cover all specified frequencies from 40kHz to 640kHz.

 

FEATURES Gen2 protocol reader engine ISO 18000-6c Compact size Low power Easy implementation

APPLICATIONS UHF RFID reader systems Point-of-Sale (POS) equipment Currency readers Toll systems

 

 

austriamicrosystems / AS3990/91