A low power CMOS sigma-delta readout circuit for heterogeneously integrated chemoresistive micro-/nano- sensor arrays

A low-power read-out circuit design for a heterogeneously integrated chemoresistive micro-/nano-sensor arrays is presented. The circuit is based on a sigma delta modulation architecture, to reduce power consumption and to allow for a wider range of resistance measurements. The design and layout of the circuit, in 180nm CMOS is presented, along with measurement results from the prototype IC. The chip successfully reads out resistances ranging from 20kOmega to 600 kOmega with a measured power consumption of 3 mW. The die area occupied by the readout circuit is 180 um times 300 um.