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How to decouple a KL27Z circuit?

Question asked by kicad1978 on Sep 30, 2016
Latest reply on Oct 4, 2016 by kicad1978

Dear community. Let me ask straight, How do I properly decouple a Kinetis KL27Z? I use it as a controller for a simple PC-USB-Keyboard. I've read the datasheet and application notes, but I got stuck with certain questions. I'm using the inbuilt voltage regulator, and +5V comes from VBUS into VREGIN. Here my questions:
-- how many bypass capacitors (0.1µF) are needed, and at which pins?
-- how many bulk capacitors (2.2µF) are needed, and at which pins?
-- if (do I?) have to use a 2.2µf between VBUS and VREGIN, where do I have to place it, near the USB connector, or near the MCU?


The power pins that are candidates for decoupling are:
VREGIN (fed with +5V from USB)
VOUT33 (+3V3)
VDD1 (+3V3)
VDD2 (+3V3)
VDD3 (+3V3)
VDDA (+3V3)
VREFH (+3V3)


best regards, from a KiCAD user.