Checking Microcontrollers And Its Supply Unit

[muashr]

Hi,

A microcontroller (used in a complicated power supply) assumed to be damaged since much higher input voltage is present at its input pins than allowed. In this regard, I have two questions

1. What would you prefer to measure voltages/values at different pins of the microcontroller, a multimeter or an Oscilloscope? If Oscilloscope, why? And what would you measure (I mean what would you look for?) using oscilloscope? What should be special settings, if any, for the oscilloscope?
2. What are the most commonly used ICs or circuits used to power microcontroller?

The microcontroller's used is **broken link removed**!

 

[Electronics4you]

What would you prefer to measure voltages/values at different pins of the microcontroller, a multimeter or an Oscilloscope? If Oscilloscope, why? And what would you measure (I mean what would you look for?) using oscilloscope? What should be special settings, if any, for the oscilloscope?

What is the microcontroller used for in the power supply circuit? If the MCU is involved in the switching circuit, only an oscilloscope will do any good. A multimeter is only used to check pin levels in low frequency circuits because multimeters only update like 2-3 times a second. Oscilloscopes can visually show signals at 20-60 MHz (low end oscilloscopes). You need to explain your circuit in more details, since an oscilloscope can show a lot of things.

What are the most commonly used ICs or circuits used to power microcontroller?

If you are building a standard microcontroller circuit with plenty of available power and want to keep it simple, you can use the LM3940, LM2937-3.3 or the LM2937-3.3, but they depend on you input voltage and the total sink current from the MCU. Do you have some additional design criteria?