New UHF Battery-Assisted Passive RFID chip incoprorates temperature sensor and SPI interface

March 29, 2012 // By Paul Buckley
EM Microelectronic, the semiconductor company of the Swatch Group, has introduced the EM4325, a versatile and multipurpose, battery-assisted passive (BAP) RFID chip with integrated temperature sensor.

The device facilitates the expansion of established UHF RFID applications by offering longer read range, increased communication robustness and more configuration options and interface capabilities for auxiliary functions. EM Microelectronic designed the EM4325 with an advanced feature set which leads to performance and functionality well beyond that of ordinary Gen2 chips.

Operating in the UHF frequency range, the EM4325 is compliant with the following standards:

ISO/IEC 18000-6 Type C and Type D (TOTAL)
EPC Class 1 Gen2 / EPC Class 3 Gen2
ATA 2000

EM4325’s BAP RFID technology combines the lower complexity, simpler communication protocols and lower cost of passive RFID with significantly higher read range and increased communication robustness available with active RFID. The EM4325 operates in both BAP and purely passive modes. It integrates smart power management for longer battery life when used in BAP applications. The EM4325 also allows programmable duty cycle and automatic switching between battery-powered and field-powered operation when the tag is too far away from the reader. An ultra-low power (ULP) mode can be activated or disabled via a simple reader command. The ULP mode extends tag battery life when the tags are stored for long periods.

The EM4325 further contains 4 kbits of high speed, non-volatile memory (EEPROM). It supports either ISO or EPC data structures compliant with EPCglobal’s Tag Data Standard, Version 1.6. To ensure full traceability, the chip is delivered with a factory programmed and serialized Unique Identifier (UID).

An integrated temperature sensor monitors temperature from -40 to +64°C. In pure passive mode, the temperature sensor can be used for field-powered snapshot readings. But the chip can also be programmed to perform self-monitoring with user-programmable alarm conditions (upper and lower temperature thresholds). The sensor may also be configured to provide Simple Sensor Data reporting according to the data formats defined in ISO/IEC 18000-6 and ISO/IEC 24753.

A key feature of the EM4325 may be the inclusion of a programmable