Ultra-Low-Power Sensor Signal Monitoring and Impulse Radio Architecture for Biomedical Applications

Remote diagnostics of patient´s vital information and initiation of necessary actions have resulted in the development of wireless body area network (WBAN). For almost zero maintenance of each sensor node within a WBAN, each node must work with a power consumption less than 100μW which can be achieved employing impulse radio architecture. In this work a low-power transmitter has been presented. The unit manifests a Data Generator Block, an Impulse Generator Block and a Buffer. The Data Generator Block converts any electrochemical sensor current in the range of 0.2μA to 2μA to digital data. The circuit can operate with a supply voltage of 1V and consume a power in the range of 0.427μW to 3.5μW. The Impulse Generator Block utilizes a RC network to generate impulses of approximately 110ns duration. Finally a Buffer circuit is used to drive a standard 50Ω load which could be an external antenna. The peak current consumption of the impulses is 2.81mA with peak output voltage of 140.2mV that makes it extremely suitable for short range wireless communication. The entire system has been designed and simulated using 0.35-μm standard CMOS process. The average power consumption of the system is only 68.30μW.