Low power high speed CMOS interface for MOS gas sensors

A universal CMOS integrated MOS gas sensor interface for application development and sensor research is presented. Three different integrated heater sources with a maximum output range of 20 V and 40 mA and the possibility to operate an external transistor as current source with an output range of several hundred mA allow the operation of nearly all kinds of hotplates. Two different readout electronics for the sensor's resistance work within a range of 1 kΩ up to 10 MΩ with a constant voltage or constant current sensor bias. All measurements are digitized with two free configurable high speed low noise analog channels which allow fast and low power measurements. The configuration of the chip and the readout of the measurements are done with a register based SPI interface.