Patent ID: 8043563
Filing Date: 2011-10-25
Classification: G01N

Abstract:
1. An electronic biosensor arrangement comprising a receiving region for biological material, a sensor-electrode arrangement with sensor electrodes which intermesh in a comb-like manner being associated therewith, a measuring circuit to which the sensor electrodes are connectable for measuring an electrical measurement parameter on the sensor electrodes and influenced by biological material during use, said biosensor arrangement further comprising a reference capacitor with which a first switch driven by a control logic and arranged for optionally connecting one side to earth or to a first voltage source carrying a measurement voltage is associated, wherein the sensor electrodes form a plurality of sensor capacitors, with which a first group of switches driven by the control logic during use are associated for selectively connecting one side of the sensor capacitors to the first voltage source, respectively, wherein other sides of the sensor capacitors are combined in a node, which is connected to a first input of a differential amplifier, wherein separate measurement capacitors having binary-weighted capacities are furthermore connected to the node for forming an SAR (Successive Approximation Register) comparison unit, with the measurement capacitors being also selectively connectable via a second group of switches driven by the control logic to a separate, second voltage source carrying a fixed voltage for the purpose of providing charge-difference for SAR conversion during use, wherein the control logic is arranged to: