Maxim has launched the industry's first ASIL-grade power protection device for cameras in vehicles.
Many of today's vehicles feature multiple cameras that, combined with other advanced sensors such as radar and LiDAR, support safety features like advanced driver assistance systems (ADAS). The fusion of these sensors detects blind spots, pedestrians, street lanes, and more. Given that these car cameras play such a critical role in safety, it's imperative to ensure that they are powered properly, operate reliably, and comply with the Automotive Safety Integrity Level (ASIL).
Automotive cameras can be supported by various power management schemes, covering the path that spans from the car battery providing the power source to the remote cameras themselves. Maxim's MAX20087 camera protector IC is the industry's only ASIL-grade camera protector (complying with ASIL B through ASIL D) with integrated I2C-based diagnostics. As a dual/quad device, the MAX20087 provides two or four 600mA protection switches in a 4mm x 4mm, 20-pin TQFN package. With AEC-Q100 qualification, the chip operates from -40°C to +125°C.
The chip supports four cameras simultaneously, so two of the devices in parallel on the same bus support eight cameras. This protects each output individually from short-to-battery, short-to-ground, and overcurrent conditions.
With cameras are starting to replace traditional side-view mirrors in some cars, and emerging driver monitoring systems rely on cameras to assess conditions like drowsiness or distraction, the move towards higher safety standards will only continue to fuel the demand for cameras. A traditional power management architecture for automotive cameras can involve multiple chips.
If several cameras are powered by a 12V battery over a coax cable, the wide voltage swings between the battery and the cabling (which is typically 8V-10V at 0.3A per camera) means designer need to various additional devices. This includes a buck-boost converter to adjust for the different voltages, particularly during start-stop and cold-crank conditions as well as isolation against fault conditions such as overcurrent, short-to-ground, and short-to-battery.