A Constant-Power Inductive-Coupling Transmitter Using Auxiliary Driving Technique in 65nm SOTB CMOS for Low-Power Supply-Sensing Biosensing Platform toward Healthcare IoTs

This paper presents a constant-power inductivecoupling transmitter for power reduction. By applying a newly proposed auxiliary driving technique, which involves connecting additional transistor in parallel with a driving transistor, we realized the constant-power characteristics of the inductive-coupling transmitter. The auxiliary driving transistor functions only at low supply voltages, thereby saving waste power at high supply voltages. Tests conducted on a 65 nm silicon-on-thin-box test chip successfully demonstrate the constant power characteristics; the power consumed by the conventional inductive-coupling transmitter increases with the increase in the supply voltage.