I^2R
Newbie
Hi,
I'm designing a power supply for an automotive device that has sensors, some high power contactors (to drive air compressors) and a remote touchscreen display.
The raw 12V is going through a protection circuit based around a LT4356HMS-1PBF "Surge Stopper" which clamps at 27V to take care of surges load dumps, etc.
The 12 "clean" power then feeds two 1A, 5V R-615.0P packaged switching regulators. One for the microcontroller (350mA), one for off-board sensors (70mA). There is a 3rd 5V supply (not shown) in the remote dash display module (800 mA) fed by the 12V clean and CAN buss.
The 12V clean also powers large 12V contactors (driven by MOSFETS by the microcontroller) that total about 1A.
The caps shown are per the application notes for the respective controllers.
My question is, do I need to add additional caps for filtering, and to deal with the inrush of the 25 ohm coils on the contactors? They will be staged to close one at a time and will have flyback diodes.
Thanks.
I'm designing a power supply for an automotive device that has sensors, some high power contactors (to drive air compressors) and a remote touchscreen display.
The raw 12V is going through a protection circuit based around a LT4356HMS-1PBF "Surge Stopper" which clamps at 27V to take care of surges load dumps, etc.
The 12 "clean" power then feeds two 1A, 5V R-615.0P packaged switching regulators. One for the microcontroller (350mA), one for off-board sensors (70mA). There is a 3rd 5V supply (not shown) in the remote dash display module (800 mA) fed by the 12V clean and CAN buss.
The 12V clean also powers large 12V contactors (driven by MOSFETS by the microcontroller) that total about 1A.
The caps shown are per the application notes for the respective controllers.
My question is, do I need to add additional caps for filtering, and to deal with the inrush of the 25 ohm coils on the contactors? They will be staged to close one at a time and will have flyback diodes.
Thanks.
