Using eFuses and smart high side switches in ADAS applications
In today's automotive market, advanced driver assistance systems are raising the standard by enabling a safer and more intuitive driving experience.
As these systems become more advanced, the demand for cameras continues to grow.
In this video, Texas Instruments look at an ADAS surround view system and see where TI's eFuse and Smart Power switches can be placed to guarantee a well protected and space optimised design. It's clear that a surround view system has many working parts. But we are going to focus specifically on delivering power to the camera interface.
As cameras themselves grow in complexity, power requirements of these systems are growing too. In order to turn on and off these larger loads, a robust switch is required. This is where an eFuse or Smart Power switch will come into play.
Let's consider a surround system with four cameras placed throughout the vehicle. Power supplied from the car is 12V battery. And we will assume each camera operates at 6V - so a DC/DC is placed directly after the battery. Placing an eFuse at the front of each camera rail provides independent control of each camera, as well as protection on the rails at the event of a fault.
The eFuse's integrated back to back FETs provides reverse current blocking. A high side Smart Power switch can also be used here. In fact, it could be placed in the same place as the eFuse.
Now, since the high side switch does not have internal back to back FETs, an external blocking diode on each rail will protect against reverse current. The 10K resistor in parallel with the diode allows for off state open load detection.
If you want to save board space, a 4 channel high side switch is a single chip solution that can control the four cameras independently.
For more information, watch the video below.