A low power sensor-signal read-out circuit powered by inductive line

A low-power sensor signal processing circuit for implantable biosensor applications has been proposed. First of all, a read-out circuit is designed to convert the sensor signal into a frequency modulated data signal and then to modulate the data signal with a high frequency carrier for successful transmission. The chip is fabricated using 0.35mum standard CMOS process and power consumption of the chip is registered to be 100muwatt. The circuit performance meets the desired requirements with a supply voltage as low as 1.5V, and it can be powered up by an external inductive link. To mimic the concept of on-chip power transmission by inductive link, a board level design is implemented with very high link efficiency. Test results emulate the simulation results with good agreement and corroborate the efficacy of the designed system