A 4.78 µs Dynamic Compensated Inductive Coupling Transceiver for Ubiquitous and Wearable Body Sensor Network

A Real-time Capacitor Compensation (RCC) scheme is proposed for low power and continuous communication in the wearable inductive coupling transceiver. Since inductance values of wearable inductor vary dynamically with deterioration of its communication characteristics, the inductance value is monitored and its resonance frequency is adjusted by additive parallel/serial capacitors in real time. RLC Bridge for detection of the inductance variations and the Dual-edge Sampling Comparator for recognition of the variance direction are proposed. It is implemented in a 0.18 μm CMOS technology, and it occupies a 1 × 2.7 mm2 chip area. The proposed transceiver consumes only 426.6 μW at 4 Mbps data rate. The compensation time takes 4.78 μs, including 3 μs of detection and 1.78 μs for compensation process in worst case. key words: inductive coupling, low power transceiver, short range wireless communication, wearable body sensor network, ubiquitous sensor network