Infineon profet

Usual to put de-coupling Cs as close as possible to each IC across the supply lines.
 
Are the Cvsx's all necesary? Since they all share the samen power line, and there is Cvs already also.

Yes they are necessary - the inductance of the power wiring is very significant at the high speeds decoupling operates at. For high speed logic decoupling caps need to be within a few mm of the device (here the speed is likely somewhat slower, so a couple of cm might be a reasonable limit). Although this device switches its main FET slowly, the control circuitry that does this will need stable power. The higher the current being switched the larger the decoupling cap value needs to be, note.

The problem with skimping on decoupling is that the symptoms of inadequate decoupling can be varied, sporadic, Heisenbuggy, and hard to diagnose - avoid that possilibity!
 
Back
Top