In automotive design, temperature is never just a number. It’s safety. It’s battery longevity. It’s the difference between a smooth EV ride and a warranty-draining meltdown.
But despite all that, temperature sensing inside cars — especially EVs — is still weirdly old-school. You’ve got bulky thermistors glued to metal, hand-placed harnesses, and contact sensors crammed into places that were never designed to fit them.
So Melexis did something that feels almost too simple:
They made the first automotive-grade infrared temperature sensor that you can place on a circuit board like any other SMD part.
And suddenly, the entire equation changes.
A Sensor That Watches Heat Without Touching Anything
The new device — the Melexis MLX90637, a 3 mm × 3 mm surface-mount IR temperature sensor — doesn’t need to be pressed onto a busbar, bolted to an inverter housing, or glued near a battery cell.
It just looks at the target and tells you its temperature.
No contact.
No isolation headaches.
No fussy placement rituals.
For design engineers working with high-voltage systems, this is a breath of fresh air. When “touching the thing you’re measuring” involves safety clearances, insulation, and EMI worries, removing the contact point isn’t a convenience — it’s liberation.
Why This Little Package Matters
The magic isn’t only that it’s IR. Lots of IR sensors exist.
It’s that this one is:
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Automotive-grade (AEC-Q100 qualified)
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Factory-calibrated
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Digitally interfaced (I²C)
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Surface-mountable with standard pick-and-place
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Capable of 0.02°C resolution
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Wide-temperature capable (–40°C to +125°C)
In other words, it fits into the manufacturing workflow automakers already use — no glue, no brackets, no custom harnesses. Just drop it on the PCB and move on.
This is the kind of quiet improvement that saves money at scale, and saves engineering sanity at any level.
Perfect Timing for Electric Powertrains
If you’ve worked in EV design, you know the pain points:
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Busbars that form hotspots
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Inverter modules that need constant thermal watching
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Battery surfaces that heat unevenly
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Motor stators and rotors that can’t be easily instrumented
Contact sensors introduce error. They drift. They age. They only measure exactly where they touch — and sometimes, that’s exactly where the system wasn’t getting hot.
But an IR sensor with a ~50° field of view?
That gives you temperature information without physically interfering with the system. It watches the heat instead of fighting its way in to touch it.
That shift — from touching heat to observing heat — is what makes this device more than a spec sheet upgrade.
Smaller Systems. Fewer Parts. Smarter Thermal Control.
Think about what goes away when you switch to a small SMD IR sensor:
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No more point-to-point thermistor wiring
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No pigtails or harnesses
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No mechanical fixtures
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No EMI/EMC issues from long sensor leads
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No recalibration after assembly
You place the MLX90637, connect I²C, and let software do the rest.
The result?
A cleaner design, fewer mechanical constraints, tighter thermal awareness, and the possibility of smarter real-time control.
A Tiny Sensor With Big Implications
Thermal management is one of the most important challenges in the electrification era — but until now, the sensors monitoring those temperatures looked like afterthoughts.
The MLX90637 feels like the first step toward temperature sensing that actually fits the sophistication of the systems it’s monitoring.
It’s small.
It’s smart.
It’s automotive-ready.
And it asks a simple question:
What if temperature sensing didn’t get in the way anymore?
For design engineers pushing to make EVs safer, smaller, and more reliable, that’s a very good question to explore.
