I'm working on a small project in which I will use two separate PCBs each having an atmega328. Total power consumption will not peak over 150mA. PCB1 will get power from a distant (10m or so) switched power supply (I'm thinking along the lines of 5V). On that PCB I will put a MCP1702 3.3V because some components need 3.3V and thus I would like to supply everything with 3.3V. PCB2 will then also be supplied from this 3.3V. PCB1 will not have a RFM12B and probably nothing else. PCB2 will have a bunch of LEDs, buttons and a DB18S20.
Looking around and reading through the MCP1702 datasheet and looking at several arduino schematics I figured I should use:
- 0.1u ceramic on the unregulated side
- 10u electrolyt with 0.1u ceramic in parallel on the regulated side
- Am I correct in my assumptions
- Why the 0.1u on the regulated side
- Most important: does PCB2 need decoupling
Thanks in advance, Jef