MP6650 doesnt working

I bought MP6650 ic and want to drive computer fan.

The number on the ic is |BGJM. Order code, is MP6650GJL-0000-Z but I am not sure pin out is L or R side. I solder the ic as it is L.

The ic is not working.

On pwm pin, I am measuring 3.8 volt without making any connection? is it normal?

How can I be sure the ic is L or R side.

I am measuring zero voltage on out1 and out2.

Hi zefir,

Thanks for your question.
Please provide a diagram of how you are connecting the part and the voltage on each input (VCC, FG/RD, PWM), as well as everything you are measuring on the outputs.
Are you measuring 3.8V without even applying VCC?


I am adding the design of the fan side.

the input is 24 volt and then it is regulated to 5 volt with TI LDO. I measured it and I am getting exactly 5 volt.

C23 is the capacitor of the voltage in pin. I put 10 uF. also I checked 2.2 uF too.

R16 is the pwm resistor. I put 50 ohm first. (from your datasheet) But the ldo got very hot. Then I tried 45-50 kohm. nothing changed. Also I tried without resistor.

without making any connection to pwm line. I gave power. the fan started to spin a couple turns and stopped. waiting a while and the fan started spinning a couple of turns and stopped.

after this attempt, I make connection of pwm line. nothing changed.


Hi Zefir,

Apologies for the delayed response.
Do you have a more clear schematic? It’s difficult to decipher how you are connecting the part from the board layout. Could you also provide scope captures of VCC, PWM, OUT1 and OUT2?