Harnessing Power Technologies to Master Infotainment Control
Steve Knoth from Analog Devices talks about how using multi-output power management ICs can simplify the design of automotive infotainment systems.
As devices get smaller, the demand for more functionality and features grows. Digital ICs like microprocessors, microcontrollers, and FPGAs are following a trend of lowering their operating voltages while increasing their power consumption.
Microprocessors are particularly popular due to their low power consumption and high performance. They’re used in numerous wireless, embedded, and networking applications. Initially, these processors were created to help OEMs build smaller, cost-effective portable devices with long battery life and high computing performance. However, the demand for this combination of efficiency and processing power has extended to non-portable applications, such as automotive infotainment systems and other embedded applications.
In these scenarios, high-performance power management ICs (PMICs) are crucial to manage the power delivery to the microprocessors effectively, ensuring top performance.
With the rise of electronic content in cars, microprocessors have become central to various vehicle control systems. Infotainment systems, in particular, have integrated multiple functions to enhance the driving experience. These systems now often include touch screens, Bluetooth, high-definition TVs, satellite radio, CD/DVD/MP3 players, GPS navigation, and video game systems, essentially becoming complete entertainment centers.
However, developing electronic systems for cars is challenging due to the wide operating temperature range, strict EMC and transient requirements, and high quality demanded by automotive OEMs.
PMICs face two main problems in these environments: power conversion and heat dissipation. Even highly efficient PMICs generate some heat, and when multiple DC-DC converters and LDO regulators are combined in one device, the heat produced can reach significant levels. A typical PMIC package might have a thermal resistance that causes a temperature rise of over 60°C at the junction. In combination with high ambient temperatures, the junction temperature of PMICs can exceed +125°C, especially in enclosed electronic modules where temperatures can hit +95°C. As a result, many PMICs rated at +85°C or even +125°C may not perform well under sustained high temperatures.
An essential feature for PMICs in high-temperature environments is the ability to self-monitor their die temperature. If the junction temperature rises too high, the system controller can reduce power to the load. This might involve turning off less critical functions or lowering the performance of processors and other high-power functions like displays and network communications.
Vehicle dashboards are crowded with electronic devices, including various types of radios and network connectivity modules. Therefore, it’s crucial that any additional components introduced into this already thermally constrained environment do not contribute to excessive heat buildup.
