Title :
Near threshold RF-only analog to digital converter
Author :
Gadfort, P. ; Franzon, Paul D.
Author_Institution :
Dept. of Electr. & Comput. Eng., North Carolina State Univ., Raleigh, NC, USA
Abstract :
This paper describes an analog-to-digital converter (ADC) capable of operating in a RF-only circuit topology. A major limitation to direct RF-powered sensors are the lack of analog circuits. The proposed architecture is comprised of a cross-coupled pair of inverters, which act as the comparator for the ADC. This setup has been simulated in IBMs 0.13 μm bulk CMOS process for a 3 bit analog-to-digital converter (ADC). At a RF supply voltage of 300 mVRMS and frequency 13.57 MHz, the ADC has a resolution of 20 mV and can resolve voltages ranging from -80 mV to 80 mV, and at a frequency of 915 MHz the ADC can resolve voltages ranging from -140 mV to 140 mV. In order to optimize the ADC operation, the sampling time has been adjusted to one-third of the evaluation time, to give the comparator enough time to complete the amplification.
Keywords :
CMOS integrated circuits; analogue-digital conversion; ADC; RF-only analog-digital converter; RF-powered sensor; bulk CMOS process; size 0.13 mum; voltage -140 mV to 140 mV; Analog-digital conversion; Computer architecture; Inverters; Radio frequency; Radiofrequency identification; Topology;
Conference_Titel :
Subthreshold Microelectronics Conference (SubVT), 2012 IEEE
Conference_Location :
Waltham, MA
Print_ISBN :
978-1-4673-1586-9
DOI :
10.1109/SubVT.2012.6404321