The challenge facing automotive designers today is that applications such as advanced driver assistance systems (ADAS) and infotainment call for an increasing amount of 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.
On top of that, the operating environment of a car is quite different from a data center. Data center servers have plenty of cooling capacity; however, in cars, it's another story. Cars operate in an environment with wide ambient temperature ranges that can reach 125 degrees Celsius or higher. 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.
Server Processors in a Car
The new generation of automotive processors require anywhere from 60 to 90 to 100 watts of power. They have essentially become server processors in a 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) have become more important than ever.
PM for Automotive Infotainment Systems
Let's consider automotive infotainment systems. Power management ICs (PMIC) 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. As a result, 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.
Key Criteria for Automotive Applications
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.
What PM Challenges Are You Facing?
Automotive-qualified PMICs have become critical for the new generation of automotive processors. They not only simplify automotive power designs by reducing overall PCB component counts, but also ensure high power efficiency and performance. Are you facing a power management challenge in your automotive design, tell us about it.