Choosing PMICs for Automotive Applications

Choosing PMICs for Automotive Applications

A single server processor in a data center might consume 200-450 watts. It's a good thing data centers are temperature-controlled environments and their servers are designed with cooling capabilities. But what if that server was inside a car, with its wide ambient temperature ranges that can reach 125 degrees Celsius or higher?

This is the challenge facing automotive designers, as applications such as advanced driver assistance systems (ADAS) and infotainment call for continually increasing in-vehicle processing power. For example, to address these needs, NVIDIA has announced what engadget is calling a "liquid-cooled supercomputer for cars." Its Drive PX 2 chip offers the power equivalent of 150 MacBook Pros, with 12 CPU cores, 8 teraflops worth of processing power, and the ability to achieve 24 trillion operations per second. All of this horsepower is necessary to run the sophisticated algorithms—including deep learning—and perform the computations that enable vehicles to do more autonomously.

While data center servers have plenty of cooling capacity, in cars, it's a challenge. Liquid cooling, used in our earlier NVIDIA chip example, offers a way to reduce operating temperature via fluid coolants pumped through microfluidic channels on a chip. Already, the new generation of automotive processors require anywhere from 60 to 90 to 100 watts of power. They have essentially become server processors in the car. As a result, as we progress up the levels of autonomous vehicles, automotive processor power requirements are only going to go up even more. That means that automotive power management ICs (PMICs) play a critical role with the expectation of meeting some unique requirements.

Autonomous driving functions are making power management for cars even more critical.

Meeting Thermal Constraints While Minimizing EMI

Let's take automotive infotainment systems as an example. PMICs supporting these types of systems must provide high switching frequencies to minimize the solution size. It's also important for them to minimize electromagnetic interference (EMI), as EMI can wreak havoc on the performance of a vehicle’s many sub-systems. These PMICs are typically attached to the main vehicle battery. Because of this connection topology, these parts should be able to withstand high input voltages (>36V) and also be able to reliably perform through load-dump events for the life of the vehicle (even though separate circuitry generally manages this battery-related phenomenon). In addition to very specific load transient requirements (typically from half to full load within a microsecond), automotive PMICs must also meet thermal requirements and constraints.

Consider IC voltage regulators. Regulators are typically attached directly to the battery power mains and are rated for 28VDC to 40VDC to handle the transients that slip through the surge and overvoltage protectors. (Downstream regulators that aren’t attached directly to the battery don't need high-voltage input specification.) Switching regulators with high efficiency (> 90% efficiency at full load) and low quiescent current can help extend battery life while generating less heat and taking up less board space—two key criteria for automotive applications.

Maxim offers a broad portfolio of automotive-qualified PMICs that work with any microprocessor or microcontroller. They're backed by a roadmap designed to address the increasing power requirements while also meeting automaker specifications for efficiency, solution cost, and footprint. If you're facing a power management challenge in your automotive design, please contact your local sales representative to learn how our PMICs can help you address the challenge. To learn more, you can also refer to our application note, "Auto Radio Head Units: More Demands, Harsh Environment Drive Need for Sophisticated Power-Management ICs."