April 10


Understanding The Power Supply De-Rating Specification

In general, for AC-DC power supplies and DC-DC converters, the recommended de-rating curves of output power are provided according to the combination of various conditions such as operating voltage, temperature, and airflow. End-product designers could select power products based on this information. The de-rating operation is to ensure the safety of power system, heat dissipation performance, and reliability. Our clients are widely spread all over the world and the operating voltage, the temperature, and the environment of different markets differ. Therefore, it is essential to ensure the stability and reliability of power system. Violating the design rules and application conditions would have adverse effects on the life and reliability of power supply and end devices.

De-rating Specification

There are two common power de-rating conditions for power products: 1. Input voltage 2. Operating temperature.

Working at the recommended de-rating output power under corresponding operating conditions could alleviate the deterioration of power supply stability caused by excessive component temperature and ensure that critical components do not exceed their thermal limits.

CINCON AC-DC Power De-rating Curve

In addition to the high efficiency and good heat dissipation design of product, Cincon AC-DC power supplies provide power de-rating curves as a reference for design applications in datasheet & application note.

For example, the CFM202S not only provides the power de-rating curves based on the different input voltages, ambient temperatures, and the airflows, but also subdivides them into different packages to ensure the safe and reliable operation for product users.

For the excellent heat dissipation characteristics of Cincon Baseplate Cooling technology, Cincon also offers the de-rating curves with larger heat sinks to simulate the better heat dissipation performance when the CFM202S is attached to the metal casing of the end-user device.

CINCON DC-DC Power De-rating Curve

Cincon DC-DC converters have high efficiency and the potted package design, and the potted package design makes the internal heat conduct more evenly to the product surface. It is a safe range of operating temperature below the maximum case temperature. In addition, the power de-rating curves are provided in datasheet & application note as a recommended reference for design applications while the installation of heatsinks for the DC-DC converter is considered.

In actual applications in end products, due to different heat dissipation conditions, there are different thermal resistances and different safe values of de-rating output power. Therefore, efficiency vs. Io load curve and Pd vs. Ambient Temperature curve are provided in the application note to allow end-product designers to calculate the safe de-rating power within the specification requirements.

Efficiency vs Io load curve and Pd vs Ambient Temperature curve:

Pd vs Po Curve and Pd vs. Ambient Temperature curve:


For example, Vin: 180Vdc, Current Load 100%, the power dissipation could be calculated by comparing the Efficiency, which allows designer to understand what the output power would be at the corresponding ambient temperature.For instance, Vin: 180Vdc, Output Power 90%, check the Pd vs. Po Curve to find the corresponding power dissipation to know how the power product operate at that ambient temperature.Cincon power product specifications (including power product with heatsink) were verified by constant temperature equipment at the same ambient temperature. However, in general, the actual temperatures inside and outside the end products are not the same. There is even a larger difference of the temperature between the inside and outside of many end products with the metal case. Therefore, Cincon power products have more eye-catching heat dissipation performance while they are attached to the chassis of end device.

In the trend of downsizing end products in the market, product designers have higher requirements for power supply dimension, power density, and operating temperature. How to provide a stable and reliable power supply with high quality for fanless applications is an ongoing goal for Cincon. As a power supply design expert, Cincon continues to strive for optimization. Based on many experiences and practical product applications in different markets shared by Cincon partners, in the future, CINCON will develop and release more power products that meet market demands, making it more convenient for end-product designers.


You may also like

{"email":"Email address invalid","url":"Website address invalid","required":"Required field missing"}

Submit your enquiries today