A sub-GHz low-power wireless sensor node with remote power-up receiver

A fully integrated low-power sub-GHz sensor node is presented for wireless sensor networks (WSN). The sensor node features a sensor IC and a RF transceiver IC, vertically assembled in a single QFN package. A unique remote power-up scheme is configured to supply the power to a sensor node from power-down state. It features a technique of centralized remote power-up scheme combined with local broadcasting power-up sequence to achieve ultra-low standby current, fast power-up time, and extended coverage. It proposes a time division switch to separate power-up message from data information, both propagated at the same frequency band. The standby current in power-down state draws less than 450nA. The sensitivity of power-up receiver is -24dBm, while the sensitivity of data receiver is -103dBm. The Sensor and RF transceiver ICs were fabricated in 0.25μm CMOS and 0.18μm RF CMOS, respectively.