Enhanced Power Modules Increase System Reliability

Power solutions impact system reliability in many ways, some more obvious than others. On the first order, a system generally needs to start up to be considered to be functioning, and since no electronics or electrical systems work without power, simply being capable of being turned on is the core measure of reliability. Beyond just being turned on, a system’s performance can be tied to the quality of power delivery. Power quality can be associated with how tightly the voltage is regulated (for variations in input voltage or output load), what kind of transient or load step can be accommodated without making the power supply unstable or exceeding the acceptable limits, how quickly or smoothly the output voltage rises, and what safety regulations/standards need to be met to garner the required reports/certifications to legally ship the product.

As hinted above, power supply regulation can apply to the input as well as to the output. Even if working on the output side is satisfactorily accomplished, reflected input noise can impact other devices that share the same line or bus. Cross-interference scaled across many units can affect the reliability or stability of the utility. Requirements for power factor correction (PFC) in AC/DC power supplies or total harmonic distortion (THD) limits address this, though they are unrelated to end-system performance.

Many electromechanical components physically connect power supplies with their loads—these are frequent points of failure in electrical systems. Connectors, wire harnesses, wires, and solder joints are common suspects in failure analysis. Components with moving parts, such as switches and fans, also present reliability concerns. Filter components like capacitors, transformers, and inductors come next. A capacitor’s reliability depends heavily on electrolyte materials, which can evaporate or outgas under thermal or electrical stress (e.g., ripple current). Magnetic components may be hand-assembled and complex, introducing additional stress-related reliability risks (e.g., core saturation).

Power supplies often feature custom BOMs, high part counts, and high power density, yet must be built safely and consistently at scale. Even basic-looking designs are often the product of years of iterative development. During design, engineers follow derating guidelines to add safety margins to critical components—e.g., operating well below the rated voltage, current, or temperature limits.

These derating values, based on decades of data, help engineers avoid over-stressing parts. Designers also apply statistical tools like the Arrhenius equation to model failure rates based on thermal exposure over time. These predictors, combined with design experience, form the basis of quality management systems (QMS) and documentation. Recognized standards like ISO 9001 guide these systems.

Magnetics are particularly critical due to their size, complexity, and role in isolation. Engineers must carefully optimize both electrical and mechanical aspects of transformers and inductors. These large components also face physical stress from vibration and shock, so secure mounting is key. Testing frameworks—such as highly accelerated life tests (HALT) and highly accelerated stress screening (HASS/HASA)—stress the unit under test (UUT) under extreme conditions to expose failure points early. These tests simulate long-term operation within a shorter timeframe.

Given that electromechanical components are often reliability bottlenecks, newer designs aim to eliminate or minimize them. Fans, for instance, can be replaced with thermal management techniques like heat spreading or reduced power consumption via intelligent power control. The use of wide bandgap semiconductors (e.g., GaN and SiC) also increases system efficiency, reducing heat dissipation and improving reliability. Surface-mount (SM) packaging is replacing through-hole (TH) components, allowing better heat transfer and automated assembly. Techniques like 3D power packaging (3DPP^®) also improve heat dissipation and enable compact, reliable designs.

Automated magnetics—like planar transformers—replace hand-wound coils with PCB-based windings, reducing size and increasing consistency. These enable better conformal coating and hermetic sealing, protecting the system from environmental hazards like humidity or conductive particles. Modern tracking systems now trace each component’s source, lot, and manufacturing path—from kitting to rework. This level of traceability helps root cause analysis and ongoing optimization. Tracking can also verify adherence to safe thermal profiles in solder ovens or identify issues caused by incorrect manufacturing shortcuts.

Any system is only as reliable as its weakest component, and power modules are often the focus of system reliability efforts. With their complexity and impact on the entire system, improving these modules can significantly elevate overall system durability. Decades of research into the physics of failure provide today’s engineers with practical tools, from derating guidelines to accelerated testing methods. While originally developed for telecom or military applications (e.g., IPC-9592B, MIL-HDBK-217), these standards can be applied to other sectors for reliable, affordable consumer products.

Modern power modules offer high reliability and compatibility with today's manufacturing processes. Through advanced packaging and off-the-shelf integration, engineers can build robust systems leveraging the best available commercial power solutions.