A 0.4-1.4V 24MHz fully integrated 33µW, 104ppm/V supply-independent oscillator for RFIDs

In RFID-tags with pulse-based UWB communication, accurate supply-independent low-power oscillators are required. The 24 MHz oscillator presented was realized in a 130 nm CMOS technology. It has an ultra-low supply voltage dependency of 104 ppm/V over a voltage range of 1.4 V to 0.4 V. This was achieved by the use of two nested ultra-low-power voltage regulators and a novel circuit technique based on the attraction of two oscillator frequencies. The mean power consumption is 33 muW over the 1 V voltage span. No external biasing and no trimming or calibration was used.