DigiKey carries a dizzying variety of devices and components, many of which are qualified to ‘Automotive Grade’ via the AEC-Q100, AEC-Q200, or related standards. These qualifications are usually attached to passive components such as diodes, resistors, or capacitors. We also carry a significant number of parts which carry medical qualifications, often in the form of power supplies. Very rarely, however, do you see a product that carries both. We’ve had a few interesting questions recently asking if this is intentional, or if an automotive qualification can stand in for medical qualifications if one is seeking medical-qualified components in a product category that doesn’t normally carry them. Is this a thing?
To answer the most important question first: Medical qualifications and automotive qualifications are two entirely separate things that have nothing to do with each other, and CANNOT substitute for each other. While both appear to be an ‘elevated quality’ standard and would superficially seem to be at least broadly comparable, each one serves fundamentally different purposes.
“Automotive-grade” products are termed such because they are manufactured to withstand the extreme stresses placed upon electronic components for use in automotive vehicles. These components must work exactly as they need to every time across a vast gulf of temperature ranges, through exposure to adverse outdoors conditions, and for many thousands of miles’ worth of work. These products are scrutinized and held to rigorous standards in order to avoid costly and potentially fatal roadside accidents and expensive downtime and maintenance. Automotive-grade qualifications are a component-level standard - the individual components that make up a system must be automotive-qualified as it is those components that must endure the conditions they’re placed within in order to avoid failure and compromising the systems they’re part of.
“Medical grade” products are termed such because they’re designed for use in a medical setting, where equally stringent standards are in place to ensure patient care and safety. A medical-grade device is one designed in a way that makes a patient-harming failure as unlikely as humanly possible, with redundancies and ‘safe-fail’ engineering alongside product testing and inspections to ensure that even if the product somehow goes bad, it does so in a way that won’t cause further harm to patients. Medical grade qualifications are generally a system-level standard - the individual components of a medical system are generally not subjected to any especial stress or extreme conditions, but the overall system must be built in such a way as to avoid harmful failures. This is why medical qualifications are generally attached to devices such as power supplies, rather than to individual components such as resistors - the final system is what matters, not the subcomponents within it.
This is also why the two qualifications very rarely meet - AEC-Q and similar standards are concerned with ensuring components are able to withstand extremely harsh conditions without failure, while medical standards are concerned with ensuring systems cannot fail in a way that harms patients. While both can be considered ‘elevated quality’, they have almost entirely unrelated end goals and very little general overlap with each other.