PWM -- MOSFET through the Darlingtion Array or Direct to Pin ??

[joe paul]

Hi Folks,

I have been always bypassing the Darlington array on the 18M2 project board when using a MOSFET with the PWM.

Can the MOSFET go into the array? Any loss of speed or control, or does the Darlington add some protection to the 18M2 chip?

Thanks!

Take care, Joe.

 

[rossko57]

Much depends on the particular MOSFET. The standard darlington does not drive its output high, only pull it low or let it float. Also bear in mind it has an inverting effect - Picaxe output high causes darlington output to pull low.

 

[joe paul]

Hi Rossko57,

Thanks for the help and information! I have used the circuit from the manual, but added the 100 ohm resistor directly to the PWM pin. I forgot about that high/low thing! I have bent or broken off the corresponding pin on the left side of the Darlington in the past.

Take care, Joe.