Please can you help me someone? I'm out of ideas.
I am trying to make power supply for 12V 0.9A LED white chip dimming with ESP32S3 by 24V power supply. I use LM3404HVMA/NOPB. I progressed by this tutorial and change values by this calculator. So I have this schematic, but nothing happend. ESP runs fine there is no problem. I have still output about 4.5V and no reaction for dimming and no reaction for enable jumper. Can have anyone idea what I am doing wrong?

Thank for your help

 

Look at the data sheet for the LM3404.
Is there voltage on VCC pin 7.
Is the voltage on RON and DIM in the right range?
What is the voltage on CS?

 

Thank you for you replay. Yes I try find anything helpful in datasheet, but nothing...
So If i turn off ESP, I have 7.09V on VCC pin7, no voltage on CS pin and 1.68V on RON..

 

VCC should be in the 6.4 to 7.4V range.
Ron needs to be above 1.05V.
When there is LED current CS = 0.2V. Is it close to 200mV.
DIM should be above 2.2V. What is its level?

 

On DIM with disconnected esp32 I can't measure anything. If I connect ESP and I will send there 3V3 logic PWM signal ESP restarts. If I cut the path from esp32 to DIM pin ESP running well and I can measure PWM signal. So Ron is 1.68V and not 1.06, so there is some problem?

 

So Ron is 1.68V and not 1.06, so there is some problem?

No problem. The voltage needs to be more than 1V.

Ron and DIM are the two common ways to shut down the IC.

 

So where can be problem? Do you look on my schematic? Is it everything okay from that? Very thanks for your helping, but I dont have idea what I doing bad....

 

Ron without jumper is connect to ground and with jumper have 1.68V, VCC have 7.09V, on BOOT I have 6.68V, VIN 23.81V, on CS I can mesure nothing, in SW I have 4.29V. DIM without connecting to ESP has nothing and if I connecting ESP with 3V3 PWM signal restarting every second and I cant mesure enything.

 

Okej I check ESP and it restart every time when I send signal more than 28 (from 255 maxim) of signal.

 

Very simple advice for ANY PROJECT you attempt to build. Use the divide and conquer method.
In this particular instance, divide into the LM3404 and the ESP32. Make them independent circuits and make sure that they work prior to connecting them together.
In this instance, build a standalone LM3404 circuit and make sure it works fine on its own.
Do the same with the ESP32.
After both are working correctly on their own, then you can marry them.
In the future, do this strategy for every system you design. Believe me that there will be projects which may comprise 5 or more individual building blocks.

 

Thank you for the advice. I try to apply it as I can. The whole project has more parts that this. I was cutting wire between ESP and LM3404 and now I messure 5V on DIM and I have 24V on output. Why?

 

Edit: Now I have 24V Input, SW 20.9V, BOOT 24,7V, DIM 5,5V, VCC 7.1V, RON 1.68V, OUT 20,7V

 

No one has an idea? I was try it again without ESP only with LM3404, 24V IN and still with the same result.