Teensy 4.1 reliability issues


New member
We've got about 20 x Teensy 4.1 in daily active use in an automotive/24v environment (industrial mobile plant). Each Teensy is connected to the 24v vehicle supply via a OKI-78SR 5V and decoupling capacitors. Both CAN interfaces are connected via 2 SN65HVD230D drivers.
We're seeing some reliability issues, approx. 1 Teensy is failing per month - so a MTBF of about 8000 hours which doesn't seem very good.
I'm guessing that the vehicle 24v supply is fairly harsh and I don't have enough supply conditioning to protect the Teensy board.
Can you recommend best practices that I should be following to keep the boards alive?
Best regards,
One suggestion: buck convert down to 8V, then use a linear regulator to get a clean 5V from there. Defence in depth. Simple buck converters have a path between input and output that becomes a short circuit if the inductor saturates. Inductors can deteriorate over time if run hot.

The issue may not be the supply, if sensors are connected that connect to the chassis for instance (chassis could have a lot of induced noise on it in some cases, not suitable for a ground-return for logic for instance).

Do the CAN interfaces have good EMI rejection? Common mode chokes etc.?
Hi Mark,
Thanks for taking the time to respond to my question and offering your advice, its much appreciated.
I don't have common mode chokes installed on the CAN bus. I read a TI application note that spoke of potential issues with high voltage spikes can be generated that can damage the CAN driver if they are used incorrectly. I have capacitor decoupled 60+60OHM center tap along with ESD2CAN protection devices.
I'll look into implementing a strength in depth approach to the PSU and see how we go with that.
You might also consider placing resistors in series with the Teensy pins. Even 1K will go a long way towards limiting current and protecting Teensy is something really bad happens to the transceiver chip, or anything else that has a GPIO pin connected.
I have multiple Teensy in an industrial environment, each inside an enclosure powered by 24V stepped down to 5V using Mean Well DDR-15G-5. They have worked well for me about 4 years now, and they have built in protections which may be helpful for you. It may be worth trying them out, they are relatively small and clip on a DIN rail.
Hi guys,
Thanks for all the advice. I'm not really in a rack mount environment and don't have room to install the Mean Well - good recommendation, may end up using that device in the future.
I'll also look to protect Teensy GPIO with series resistors like that.