MP2905 Operation Problems

Hello,

I made a power board with MP2905.
there is a problem with the operation.

PWM 230KHz output from SW pin and 5.2V output,
But the LED connected to 5.2V does not work.

What is the problem?

Hi orbakdu,

Thanks for posting on the MPSNow Forum.
Can you please attach your schematic, showing your connections clearly?

Thanks,
Cindy

Hi Cindy

I had another problem that didn’t work.
If I remove the resistor 5.1Kohm from the ILIM pin, it works.
However, the Q100 is very hot (over 70 degrees Celsius).

Also, when power is applied, the SW pin operates at 105KHz for a few minutes and then slowly changes to 190KHz.
SW pin operates at 240KHz when there is no load

Thanks,
orbakdu

Hi orbakdu,

Thanks for providing your schematic. Could you also provide scope shots of Vout, Iout, SW, ILIM, and Vin?

Thanks,
Cindy