An ultra low power pH-monitoring IC with a duty-cycling wireless FM-transmitter

This paper proposes an ultra low power pH-monitoring IC featuring a wireless FM-transmitter with duty cycling operation and the use of an Ion Sensitive Field Effect Transistor (ISFET) for dentistry application. The IC achieves wireless communication and pH sensing under very low current consumption thanks to duty cycling operation and heavily stacked-transistor design. 0.18 μm CMOS process technology is used to fabricate a prototype chip, and current consumption of 2.0 μA was measured.