Optimizing Automotive Electronics: The Role of Derating in Thermal Management

Have you ever had your navigation system go dark, your radio cut out, or your rearview camera fail just when you needed it most—perhaps on a blazing summer day? These interruptions can often be traced to a crucial thermal management strategy called derating, which prevents overheating by intentionally reducing system performance to protect sensitive electronics.

A vehicle’s interior can reach extreme temperatures on a hot summer day, and the electronic systems inside are especially vulnerable. One of the major contributors to this thermal challenge is solar loading, which refers to the heat absorbed by a vehicle's components due to solar exposure. "This additional heat load can significantly increase the temperature or create a significant temperature gradient within sensitive electronics, such as infotainment, navigation, and powertrain systems, leading to a thermal state that may degrade performance or cause permanent damage."

This practice helps to avoid permanent damage, extend the lifespan of critical components, and ensure reliable performance in extreme environmental conditions. For thermal engineers, derating is just one comprehensive thermal management strategy tool. Engineers often design cooling systems—such as fans, heat sinks, or phase change materials—that help maintain safe operating temperatures even under challenging thermal loads to prevent sensitive electronics from reaching critical thermal states that require derating.

Real-World Applications of Derating in Automotive Systems

In practice, derating plays a crucial role in managing the thermal performance of automotive electronics, particularly under conditions that contribute to overheating, such as solar loading and high-power demands. By limiting power levels, derating safeguards components so they stay within safe temperature ranges, helping to prevent damage and maintain system reliability.

A key component in this process is the Engine Control Module (ECM), which constantly monitors component temperatures and dynamically adjusts power loads and system settings. For instance, during high heat, such as when the vehicle is exposed to direct sunlight, the ECM can lower power to infotainment displays or sensors. This strategy helps manage thermal stress, ensuring the system operates safely without compromising performance.

By carefully managing component temperatures, engineers can reduce the need for derating, ensuring that all systems remain operational even under extreme conditions.

Derating in TAITherm

How to Enable Thermal Safety for Automotive Infotainment

Modern infotainment systems have alert functions that help modify system behavior when temperatures rise above predefined thresholds. These alerts play a crucial role in system thermal management by providing multiple levels of control.

For instance, as shown in Figure 2, the first alert (THERM2) can be set at 85°C as a warning. This can trigger a fan or cooling system or reduce the microprocessor's performance to lower the risk of overheating. The second alert (THERM), set at 110°C, acts as a failsafe by shutting down the system to prevent damage. In such cases, it may signal the power supply to shut down and initiate a system reset, allowing the temperature to drop below the THERM hysteresis level before normal operation resumes.

T. Brillet de Cande, "How to Enable Thermal Safety for Automotive Infotainment and Cluster Systems," Texas Instruments, Technical Article SSZT398, Oct. 2019. [Online]. Available: https://www.ti.com/lit/pdf/SSZT398.

Balancing Derating with User Experience

While derating is essential for preventing overheating and protecting hardware, it can impact the user experience by temporarily limiting certain functions, such as display brightness or infotainment features. Engineers carefully balance these protective measures with the need to maintain seamless functionality. By employing advanced thermal design, they work to minimize any noticeable effects on the driver.

This balance is even more critical in electric vehicles (EVs), as derating can affect battery performance and vehicle range. To protect battery health, derating may limit power output or charging speed under high temperatures, impacting driving range. By designing efficient thermal management systems, engineers aim to reduce the need for derating, ensuring reliable performance without compromising user satisfaction.

The Role of TAITherm® in Thermal Management

TAITherm® is an advanced thermal simulation software that empowers automotive manufacturers and thermal engineers to predict, analyze, and optimize the thermal behavior of vehicle components under various conditions, including solar loading. Using TAITherm®, engineers can simulate how electronics, interiors, and critical systems respond to real-world thermal challenges before physical prototypes are built, which is invaluable for designing effective derating strategies.

Engineers can use TAITherm® to model a wide range of transient and extreme operating conditions, such as drive cycles, solar loading scenarios, and environmental factors specific to any location or weather condition worldwide—all with fast turnaround times. By leveraging these capabilities, TAITherm® supports the design of advanced thermal management systems that minimize the need for derating, ensuring reliable performance under even the most demanding conditions.

A visualization of the temperature distribution in an in-vehicle component alongside a plot showing the component's temperature over time, both generated using TAITherm® thermal simulation software.

TAITherm® plays an essential role in electric vehicle (EV) design, where thermal management is closely tied to battery performance and range. By simulating battery behavior under different temperatures and charging scenarios, TAITherm® enables engineers to optimize battery placement, cooling, and charging strategies to minimize overheating and reduce the need for derating measures that could limit vehicle range. This proactive approach to thermal design helps manufacturers maintain EV efficiency and reliability across various climates and driving conditions.

Simulating thermal behavior before production offers additional benefits. It allows engineers to validate designs, optimize materials, and make targeted adjustments before committing to costly tooling and manufacturing. This approach reduces the risk of overheating, shortens the development cycle, and ultimately enhances reliability and user satisfaction.

Conclusion

Derating is a key strategy for enhancing the reliability and lifespan of automotive electronics, particularly as vehicles face increasing thermal stress in high-temperature environments. By limiting component strain and controlling heat, derating mitigates risks of overheating and helps essential systems – from infotainment to battery management – operate safely and effectively.

TAITherm® empowers engineers to design confidently, proactively managing derating strategies through accurate thermal simulations. This allows manufacturers to optimize thermal performance from the earliest design phases, reducing development costs, minimizing the need for expensive late-stage design changes, and ensuring that vehicles can withstand real-world conditions without compromising user satisfaction.

As automotive technology evolves, derating will continue to be essential for reliable vehicle performance, helping to prioritize safety and durability in all climates and conditions. For a deeper look into how TAITherm® can support your thermal management needs, contact your account manager or request a demo on our website to explore the benefits firsthand.