A 640 µW frequency synthesizer dedicated to implantable medical microsystems in 90-nm CMOS

摘要

This paper presents a 90-nm CMOS, ultra-low power frequency synthesizer dedicated to implantable smart medical devices. A new supply regulated LC-VCO that reduces the impact of process variations and temperature on current consumption and phase noise is proposed, as well as a new single-ended charge pump architecture that offers very high output impedance over a wide output voltage range. The frequency synthesizer operates in the 902–928 MHz Industrial, Scientific and Medical (ISM) band. It allows the selection of 7 channels 3.4 MHz in bandwidth and provides the differential, I/Q versions of the RF carrier. The measured power dissipation of the frequency synthesizer is 640 µW.