I stuffed up 250 times

[24602]

I stuffed up 250 times

So sent to fab 250 pcbs with an incorrect way of switching/ dimming these LEDs from a ESP32 (Via header on left). By High side driving these LEDs using these particular mosfets results in a working but very dim LED.

Schematic Attached

The mosfet is a SOT23 part.

 Is there a drop in part replacement to get this working? Trying to avoid having to bin a bunch of boards.

(5x RGBW LEDs)

[xavier60]

Try an NPN BJT.

[Andree Henkel]

or a PMOS FET / pnp bipolar
needs ofcourse inverting the control voltage (output level of µC in firmware)

[Ian.M]

This has come up before.  IIRC source/drain pinout swap SOT-23 MOSFETs are vanishingly rare, and *IF* you find one, you still have the problem of the gate pulldowns, which obviously should be pullups.    Also you'd need a 5V logic high level but the ESP32 PWM is only 3.3v.

A better solution would be to create a little interface board to provide approx 10V gate drive, which will let those high side N-MOSFETs work just fine.

[24602]

This has come up before.  IIRC source/drain pinout swap SOT-23 MOSFETs are vanishingly rare, and *IF* you find one, you still have the problem of the gate pulldowns, which obviously should be pullups.    Also you'd need a 5V logic high level but the ESP32 PWM is only 3.3v.

A better solution would be to create a little interface board to provide approx 10V gate drive, which will let those high side N-MOSFETs work just fine.

Thanks yeah, if I have to create a add-on board would be better of just re spinning these problematic LED boards

[24602]

Hi All, Ive redone the schematic let me know if there's any problems before I send to fab