i got this issue :
I've built many PCB's with atmega328p as brain and MIC5205 as 5V voltage regulator which i connect 9v battery to it as power supply " same as regular ARDUINO"
all projects worked fine as long as current does not exceeds the regulator limit which is 150mA.
now im having a project where one of atmega's pins shall provide 5V and more current than usual,
in which total system will withdraw up to 200mA from the MIC5205.
when testing, the system shuts down.
i've searched the internet and found this regulator "MIC5209" .. it can provide current up to 500mA.
my question, will replacing the MIC5205 with MIC5209 solve the problem ?
MIC5205 with the tiny SOT-23 package cannot dissipate much heat... max junction temp of the die is 125C. depending on how you designed 170 to 220C /W. At 200mA with 9V input you are at about 0.8watts. 200mA would push it past your thermal limit.
MIC5209 with the should work for for you because it's a bigger package (SOT223, SOIC 8 and D2PAK) better thermal dissipation.
4.6 Thermal Considerations MIC5209
The SOT-223 has a ground tab that allows it to dissipate more power than the SOIC-8 (refer to the Slot-1 Power Supply sub-section for details). At +25°C ambient, it will operate reliably at 1.6W dissipation with “worst-case” mounting (no ground plane, minimum trace widths, and FR4 printed circuit board).
You are also running into the Arduino current limit:
the total current sourced from all I/O pins must not exceed 200mA, according to the ATmega328P datasheet.
Is there a reason why power has to be supplied through the Arduino?
