12V to 3.3V Power Supply and automatic lock

[sugandha123]

Hi All

I have designed a circuit but. I have tested 12V to 5V supply, it is working correctly but 12V to 3.3V is not converting and ASM1117 has got burnt. I am not able to identify the issue. Kindly help me in this.

 

[KlausST]

Hi,

when a semiconductor gets damaged there are only a couple of reasosns. Mainly:
* overvoltage. Even short in the microseconds range
* overcurrent. Even short
* overtemperature by too high power disspation.

None of the above we can exclude with the given informtions.
We have no current information
We have no information about the exact type of AMS1117
We have no information about external power supply
We have no infromation about ambient temperature of the IC on the PCB inside the enclusure.

BTW: D3 is useless ... it even violates the input impedance requirement of the L7805
Did you read the AMS datasheet regarding output capacitance requirement?

added:
Did you read the AMS datasheet regarding thermal considerations?

Klaus

 

[sugandha123]

Problem is solved now. I am converting 5V to 3.3V now.
New problem is I am able to program Atmega328P but not able print the data on serial monitor through FTDI. Same code with FTDI is working on other hardware PCB but not with my PCB.

 

[jverive]

Problem is solved now. I am converting 5V to 3.3V now.
New problem is I am able to program Atmega328P but not able print the data on serial monitor through FTDI. Same code with FTDI is working on other hardware PCB but not with my PCB.

Which pins are you using for the serial monitor connection? It looks like you're using PD1 and PD2, but for most Arduino Uno designs pins PD0 and PD1 are used.