Towards Ultra-Low-Voltage and Ultra-Low-Power Discrete-Time Receivers for Internet-of-Things

In this paper, we investigate an impact of voltage supply scaling on power consumption and performance of a new class of wireless receivers (RX) for Internet-of-Things (IoT) applications: a discrete-time (DT) superheterodyne architecture realized in nanoscale CMOS using inverter-based g m and switched capacitors. The power supply is partitioned into three separate domains: RF, intermediate frequency (IF) processing, and clocking, which allows them to be independently regulated to assess their respective impact. The DT-RX maintains its functionality, albeit with some acceptable loss of performance, when the core supplies are varied by as much as an octave, i.e., from the nominal 1.1V down to 0.55V. The DT-RX IC is then connected to a switched-capacitor based voltage doubler array on a companion IC die such that the DT-RX can be powered at the octave range of 0.275-0.55V from an energy harvester. The sensitivity at the doubler's 0.275/0.55V input is -85/-95dBm while consuming 1.0/2.4mW. Both ICs are implemented in TSMC 28-nm LP CMOS.