A readout circuit for capacitive biosensors with integrated SAR A/D conversion

This paper presents a circuit for monitoring biochemical reactions on an array of capacitive biosensors. The integrated SAR A/D conversion provides a robust solution that is configurable to meet a range of requirements. In the example given, the circuit operating at 100MHz is able to read out an array of 1000 capacitors with a value of 1pF at 12.5 kHz with 6 bit accuracy