A 164-μW 915-MHz Sub-Sampling Phase-Tracking Zero-IF Receiver With 5-Mb/s Data Rate for Short-Range Applications Y

Abstract

This article presents a 915-MHz ultra-low-power (ULP) sub-sampling phase-tracking receiver (SSPT-RX). It is targeted for the power-constrained devices that need short range but medium high-speed data receiving, such as the multi-channel neural stimulator with arbitrary waveform generation. The zero-intermediate frequency (zero-IF) phase-tracking receiver (PT-RX) topology is adopted to simplify the sub-sampling RX architecture with direct demodulation of frequency-shift key- ing (FSK) signal while improving the image frequency issue. The frequency of local oscillator (LO) is reduced by ten times with the proposed architecture, which leads to greatly reduced power consumption. Fabricated in 65-nm CMOS process, the RX chip occupies an active area of 0.58 mm 2. The RX consumes one of the lowest power consumptions of 164 µW from 0.5-/1-V supplies. It achieves an energy efficiency of 32.8 pJ/bit at a data rate of 5 Mb/s, which is improved by ∼5.6× compared to the state- of-the-art RXs. The measured sensitivity of 915-MHz FSK signal receiving is −69.5 dBm with an LO frequency of 91.5 MHz, which is 1/10 of the carrier frequency. The achieved RX sensitivity figure-of-merit (FoM) is 174.3 dB. Manuscript received 21 October 2021; revised 5 February 2022 and 27 March 2022; accepted 30 April 2022. Date of publication 19 May 2022; date of current version 26 August 2022. This article was approved by Associate Editor Danielle Griffith. This work was supported in part by “Nanosystems at the Edge