A UHF RFID Chip Solution with New Oscillator calibration Scheme and 16k bits EEPROM

Abstract

A UHF RFID tag chip solution with a new oscillator calibration scheme and an EEPROM solution with memory capacity as big as 16k bits was presented. The new calibration scheme adopts a calibration command compatible with EPC Protocol, then, a field and low cost oscillator calibration is realized. To reduce the read power of the EEPROM when the storage capacity is increased to 16k bits, a global power management strategy is adopted. Thus, the capacitance load for read operation is reduced, which will result in low power consumption, and the total current consumption for the read operation is 2.26µA. The proposed calibrated oscillator and 16k bits EEPROM were then integrated and verified in a full UHF RFID tag chip. The achieved read communication range is 3m. The test results show that the calibration error of the oscillator is 5.7%, which can be further improved by adopting a large current switch array with each current switch carry smaller calibration current I_ref/M.