Integrated EMI Detector as Essential Safety Mechanism in Automotive Sensor Applications

Abstract

Advanced Driving Assistance Systems (ADAS) consist out of many electronics applications that assist drivers and take over safety critical functions. Reliable sensor data (e.g. Rain, ambient light, tire pressure, Radar, LiDAR, ultrasonic park-assist, etc.) are crucial in safety applications and might be a challenge under the existing and emerging radio fields to avoid systematic failure of the ADAS. The sensor data from some EMI sensitive ADAS sensor might not be reliable under foreseeable intended and unintended use. At that moment it's important to be able to detect the radio field that causes inaccurate/incorrect sensor data. This paper describes an integrated, accurate, frequency flat RF detector with programmable RF-immunity acceptance threshold and state of the art resolution. The EMI-detector is integrated in a Rain & Light-ADAS sensor IC that decides on the activation of the vehicle head lights and wipers. The design of the EMI detector allows to share pin-resources (it reuses the light sensor input pin and allows concurrent operation with the light sensor). To avoid availability issues the RF-immunity acceptance threshold - triggering safe state in this IC - can be programmed above the minimal EMI level for which the ADAS sensor is designed.