An EEPROM Programming Controller for Passive UHF RFID Transponders With Gated Clock Regulation Loop and Current Surge Control

This paper presents an EEPROM programming controller imbedded in a passive UHF RFID transponder. A 14 V programming voltage is generated and regulated for a 224-bit EEPROM memory array from a rectified voltage supply of 2-3 V. A gated clock regulation loop is proposed to keep the programming voltage constant over a wide range of received RF input power, in order to improve the write-erase endurance of the memory. A current surge control scheme is proposed to allow the EEPROM programming voltage ramping in steps, therefore, preventing the collapse of the rectified supply in the remotely powered transponder. Also presented is a nano-power switched bandgap reference to reduce die area through the reduction of MOmega resistors needed for nano-power operation. Measurement results show that a 0.35 mum CMOS transponder IC provides a stable EEPROM programming voltage which varies less than 8% over a large 30 dB input power range while consuming 7 muW. The EEPROM programming controller occupies 0.092 mm² die area.