What are the main challenges and trade-offs of circuit design for harsh environments?

1 Temperature effects

One of the most common and critical factors that affect circuit performance and reliability is temperature. High or low temperatures can cause thermal expansion or contraction, resistance changes, leakage currents, noise, and degradation of components and materials. To cope with temperature variations, circuit designers need to select suitable components that can withstand the specified temperature range, use thermal management techniques such as heat sinks, fans, or thermoelectric coolers, and design circuits that can compensate for temperature-dependent parameters, such as using feedback loops or temperature sensors.

2 Humidity effects

Another factor that can affect circuit performance and reliability is humidity. High humidity can cause corrosion, oxidation, condensation, and short circuits, while low humidity can cause electrostatic discharge, cracking, and brittleness. To cope with humidity variations, circuit designers need to select suitable components that can resist moisture and corrosion, use protective coatings, sealants, or encapsulants, and design circuits that can tolerate or avoid moisture-sensitive parameters, such as using conformal coating or desiccant packets.

4 Radiation effects

Radiation can cause ionization, displacement, or degradation of circuit components and materials, especially for those that have semiconductor or organic elements, such as transistors, diodes, or capacitors. Radiation can also induce noise, interference, or errors in circuits. To cope with radiation, circuit designers need to select suitable components that can resist radiation damage and degradation, use shielding or hardening techniques, and design circuits that can detect or correct radiation-induced errors, such as using error detection and correction codes or redundant systems.

5 Electromagnetic interference effects

Electromagnetic interference (EMI) can cause unwanted signals, noise, or distortion in circuits, especially for those that have high-frequency or sensitive elements, such as antennas, amplifiers, or sensors. EMI can originate from internal or external sources, such as power supplies, motors, or radio waves. To cope with EMI, circuit designers need to select suitable components that can reject or minimize EMI effects, use filtering or grounding techniques, and design circuits that can shield or isolate EMI sources or receivers, such as using shielding materials or enclosures or differential signaling.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?