First: Especially the Pi5/CM5 are sensitive to low voltage.
Does anyone knows a solution that works? Or can it be programmed that the RPI does not go asleep or auto-shuts down at lower voltage? I can't imagine that it does not work on 4,99V when it does work on 5,1V.
I made my own converter that takes anything between 9 and 36V.
Next problem: short dropouts. Maybe increase input capacitance and add same mF's of bulk capacitance on the input side if this becomes a problem.
The board shown is designed for 3A. If you need 5A you need either an USB-C PD PSE chip that tells the powered device that it is safe to draw 5V@5A via the CC lines, or you need an entry in the bootrom that disables this safety check.
Cars are especially nasty. You need automotive-grade protection devices
Example:
https://www.st.com/en/protections-and-e ... -35AY.html
This device will protect your DCDC from pulses up to +150V and -220V according to ISO 7637-2. Such pulses can occur when starting the engine. Furthermore the starter battery can drop to almost half the voltage when the electric starter is operating. All automotive-grade devices are tested against these loaddumps and against ESD spikes up to 30kV according to IEC 61000-4-2 and ISO 10605.
Statistics: Posted by fchk — Mon Aug 25, 2025 6:24 pm