Large bandwidth transimpedance amplifier for biochemical sensing applications


For a plurality of sensing applications* a transimpedance amplifier (current to voltage converter) is an essential part of the measurement system. The ideal transimpedance amplifier has an extremely low input impedance over its bandwidth. The most common form of such an amplifier is based on an Operational Amplifier (OpAmp). However, due to the gain and bandwidth limitations of an OpAmp the input impedance of an  amplifier based on an OpAmp starts to increase quickly when frequency rises. This increased input impedance makes the amplifier less suitable for use at higher frequencies. Unfortunately, there is no alternative which can be used at higher frequencies. Therefore this assignment puts its focus on the design and development of a transimpedance amplifier with a large bandwidth (>10 MHz). Implementation is possible on PCB-level or on chip level. Prototype chips can be made using the Europractice MultiProject Wafer (MPW) service.

* chemical sensing, biochemical sensors, optical sensors, component characterization, etc.


 Typical basic transimpedance amplifier.



The project comprises:

  • Identification and testing of proper materials for the hydrophobic electrodes
  • Design and simulation of valves and metering sections
  • Design of the microfluidic device and the fabrication process flow.



Andre Bossche