I am working on a project that requires a 0-5v PWM input to control a fuel pump. the input to the controller also accepts a 0-5v analog input to achieve speed control. The ECU i have has a programable low side PWM output. I can vary the frequency and duty cycle based on other parameters. the frequency will likely be fixed at 100Hz. Output from the ECU is rated at 4A max, with no internal flyback diode. i havent been able to find any further specifics on the input to the pump speed controller. Im assuming i will use a P channel Mosfet to accomplish this but i have no idea what specs i should look for. any recommendations ?

 

Assuming the 5V PWM is just a logic signal (not supplying power) you just need and inverter. Either a single transistor or a 5V logic gate could be used.

Edited: And a source of 5V.

 

Assuming the 5V PWM is just a logic signal (not supplying power) you just need and inverter. Either a single transistor or a 5V logic gate could be used.

Edited: And a source of 5V.

Im not sure how much current draw will be on the signal out. i am waiting to hear back from the manufacture. i found an older thread where @LowQCab explained using a p channel mosfet to accomplish this exact thing. i believe i would like to go this route but will likely need help sizing or selecting exact components