1 Introduction

Today’s newest vehicles have fewer knobs and buttons and instead rely on taps and swipes on a touchscreen to control a variety of functions. You can adjust mirrors and lights, turn on windshield wipers and set up your navigation. With this added functionality, the display panel size in cars is getting larger and larger. By 2025, 37-inch in-vehicle screens could be common with resolutions of 4K (on the order of 4,000 horizontal pixels) and eventually 8K. Traditional automotive displays use globally dimmed edge-lit backlight solutions but the light leakage from the LCD panel, which makes the black area not true black, could lead to a degraded viewing experience, especially when driving in the dark. Local dimming LCD backlight technology can help solve this problem.

Most of these automotive displays provide safety-relevant information through advanced driver assistance systems (ADAS) and digital instrument clusters, so they must comply with functional safety standards. The functional safety of automotive electronic/electrical systems is directed by ISO 26262. Automotive Safety Integrity Level (ASIL), which classifies the inherent safety risk in an automotive system, is an integral part of that standard. There are four ASIL levels: ASIL-A, ASIL-B, ASIL-C, and ASIL-D, with ASIL-D having the highest integrity requirements.

Automotive displays, like an instrument cluster display that includes various blocks, should meet the criteria outlined by ASIL-B. This document looks at how to meet system-level ASIL-B requirements using a TI local dimming LED Driver and LED power subsystem.