The NCV75215 ASSP is intended to operate with a piezoelectric ultrasonic transducer to provide time-of-flight measurement of an obstacle distance during vehicle parking. The high-sensitivity, low-noise operation allows detection from 0.25 m up to 4.5 m for a standard 75 mm pole. The device drives the ultrasonic transducer with a programmable frequency via a transformer. The received echo is amplified and converted to a digital signal, filtered, detected and the magnitude is compared to a time-dependent threshold which is stored in an internal RAM. A bidirectional I/O Line is used to communicate with a master (ECU). The master issues I/O Line commands to the NCV75215 and data are reported back via the same line.