A 915MHz passive read-only radio frequency identification (RFID) tag compatible with NCITS-256-1999 is presented. This tag has the advantages of low power and large dynamic range. The static current consumption of the analog front-end is 1.6μA under a 1.6V power supply. The minimum RF input power that makes the chip work properly is about 45μW. The tag has been implemented in 0.18μm CMOS technology. Measurement results show that the chip can satisfy the design target well.