ALLPCB
Overview
An EMC engineer, Lei Mao, reported during remediation work for an automotive customer that a primary common cause of frequent automotive sensor failures is unstable voltage.
Voltage fluctuations in vehicles
Voltage fluctuations are unavoidable during vehicle operation. These fluctuations can originate from engine start events, alternator operating conditions, and the switching of other electrical loads. Sensors are sensitive to supply stability, so unstable voltage can stress or damage them.
Mitigation: TVS transient voltage suppressors
One practical mitigation is to use compact, high-current TVS (transient voltage suppressor) devices on vehicle circuits. TVS devices can respond rapidly to transient overvoltage, clamping spikes and preventing the supply from exceeding a sensor's allowable range. They typically feature low leakage and fast response, which helps protect sensors from voltage excursions.
Impact on reliability
Integrating TVS devices into vehicle power distribution can reduce sensor failures, extend sensor service life, and lower replacement and maintenance frequency, thereby improving overall vehicle reliability and stability.
