Dynamic Element Matching for the Grounded Inductor Simulator Output Stage in Ultrasonic Distance Sensor Applications

This letter describes a new dynamic element matching (DEM) technique usable in a resonant circuit during reverberation measurement. Traditionally, DEM algorithms switch circuit elements during the operating cycle, which would inject periodic noise into such sensitive circuits and degrade parameters of the overall system. We describe a new approach that eliminates this problem by switching elements between operating cycles and processing results from multiple operation cycles. This new DEM technique is specifically targeted for use with a grounded inductor simulator in transformerless park assist sensors. The described DEM approach was verified using a test chip and a digital control implemented in a field-programmable gate array. Measurement results confirming performance of the described DEM approach are presented.