A 75 μW Real-Time Scalable Body Area Network Controller and a 25 μW ExG Sensor IC for Compact Sleep Monitoring Applications

A light-weighted body area network using 3-layer coin-sized fabric patches is proposed for sleep monitoring systems. It consists of two ICs, a network controller (NC) and a sensor node (SN), and also Wearable Band (W-Band) to connect them. The Continuous Data Transmission (CDT) protocol is proposed for low power and real-time scalability by in-order data transmission using W-Band among several sensors. Based on this protocol, Linked List based network Manager (LLM) and Adaptive Dual Mode Controller (ADMC) in NC, and low swing data transmitter (D-TX) and its own back-end circuits are introduced. The LLM and ADMC can adaptively change the network configuration according to the dynamic network variances in real-time ( <;500 ms), and D-TX can make low energy data transmitter of 0.33 pJ/b with 20 Mbps data rate for W-Band interface. These two low power ICs, which are implemented in 0.18 μm CMOS process and operates with 1.5 V supply, consume 75 μW and 25 μW, respectively.