MP155 explosion

Hi, I just used MP155 in my design and this is my problem:
The DRAIN Pin of IC explodes after the AC power supply enters the circuit.
This is my schematic:

Correction : L2 is 2.2mh

Hi lotfimhl:

Welcome to our community. Can you please confirm that you have used the same layout as our layout guidelines on page 15 of the datasheet?It is important to minimize the loop area formed by the input capacitor C16 , MPS IC part, freewheeling diode D8.

thanks for responsing.
Yes, I designed the PCB so that the loop is very small and I considered all the layout guidelines.
This problem has occurred every time the test is performed.

Couple of observations on the schematic:
1)The inductor, L2 is drawn as a capacitor but the inductor L1 has the correct symbol.
2)The diode D8 is drawn as a resistor but the Diode D4 has the correct symbol.

Can you please check if these devices are assembled correctly since the schematic has incorrect symbols.
Also can you please share the datasheet of the inductor?
Also I would test with the input inductor L1 shorted out. This is to avoid setting up any resonance in the Input filter formed by C14, C16 and L1 at turn on of the AC power as there is inrush current into the filter that can cause L1 to be charged up and then resonate… If that works then you may want tos oft start with a series resistor or thermistor to control inrush and also maybe add a damping resistor across L1.


For the two points you mentioned: footprints and components are correct.
The L1 connection was shortened and the same result was achieved again.
This is a picture of the some ICs that burned.

And this is a picture of PCB layout :

We observed that on your schematic the R13 value is 24.9 Ohms but on our datasheet it is 24.9K. It is likely that you are exceeding the Absolute max rating of the Vcc. Can you please try with R13 as 24.9K?
Below is the schematic snapshot from our MP155 datasheet.

You are right
This is my fault in the schematic. But the value of R3 that I used in my circuit is in accordance with your schematic.

Hello lotfimhl, Hello monolithicpower support,
is there any resolution to the problem with the MP155 series voltage regulator? I also consider using the component in a new design, but there is development kit available and this thread made me rather cautious. What is the correct value of the resistor R13?
I am looking forward to your feedback!