A -80dBm BLE-compliant, FSK wake-up receiver with system and within-bit dutycycling for scalable power and latency

This paper presents an FSK wake-up receiver with a -80 dBm sensitivity using a packet structure and a duty cycling scheme compliant with the Bluetooth Low Energy (BLE) protocol trading off power with latency. Event-driven applications achieve power lower than 240nW from a 0.75V supply while latency-critical systems wake up in almost 200μ at a 230μW consumption. A within-bit LC oscillator duty-cycling scheme is proposed to provide an extra 24% power reduction. Additionally, a custom FSK transmitter can trigger wake-up at 17nW only for an average latency of 5 seconds.