Offset Voltage Evaluation of Analog Blocks in a Configurable Mixed Architecture for Smart Capacitive Sensor Applications

The authors present a novel approach to estimate the offset voltage of analog blocks in a Cypress Programmable System on Chip (PSoCTM) mixed signal array device devoted to embedded applications for smart capacitive sensors. The offset voltages are estimated using just a simple connection of blocks housed in the architecture. When the PSoC analog circuits are to be exploited for accurate measurements or in analog conditioning paths, these offset voltages, which could reach hundreds of millivolts, must properly be taken into account in order to obtain a good reproducibility of the performance of different chips and different lots.