Design of a novel very-low input capacitance high-bandwidth buffer for a biomass sensor

Abstract

In this work, a high-bandwidth very-low input capacitance original topology buffer was designed. The proposed buffer circuitry is conceived as part of a novel non-invasive non-immersed real-time dielectric spectroscopy biomass sensor. Both a circuital-based simulation model and an experimental PCB prototype were implemented and successfully tested. The buffer effective parasitic input capacitance was lowered to a 2% of its original value by means of power supply bootstrapping. This improvement will allow performing differential voltage measurements with the required accuracy and without compromising the necessary bandwidth.