A SignalBased Clocking Scheme forA/D Converters inBody SensorNetworks

Theimportance ofbodysensor networks to monitor patients overa prolonged period oftimehas increased withan advancein home healthcare applications. Sensornodesneedtooperate withvery low-power consumption andundertheconstraint of limited memorycapacity. Therefore, itappears wasteful todigitize thesensorsignal ataconstant samplerate, giventhatthefrequency contents ofbodysignals vary withtime. Inthispaperalow-power analog systemis proposed, whichadjusts theconverter clock ratetosuit themomentaryrequirement of thesignal to be converted. Simulation ofthesystematthecircuit level showsa significant reduction intheaveragesample frequency anddatarateof50%and35% respectively compared totheconventional approach. ~~~~~P r~~~~~~~~ )