After looking at this,
I am building the following circuit, in order to control the P channel MOSFET as a high side switch for my load.
The input of this circuit will be from a microcontroller (maybe an STM32F103), and I was planning to use the output pin, in open collector mode.
Will this work? Please note that I am pulling up the pin at 12V.
I know that in other circumstances it would work, but in a microcontroller, will the output handle the 12V? When in open collector, are the ESD diodes disconnected?
And if it works, how do you handle the initialization of the pin, (after reset, before configured as an open collector pin).
I think I already know the answer, but I just wanted some clarification.
I have a part that is going to drive my mosfet at 15V. I have thought about putting in a 10K resistor on the gate and pulling it to ground through the atmega48 microcontroller and sink the current 1.5mA to force the gate to ground. According to the datasheet Port B can sink/source current.
I know from the datasheet that I can sink 10mA per pin at 3.3V with the Atmega48, but based on the datasheet it appears that only ADC4 and ADC5 pins will allow it and I need 4 pins.
So it appears that I have two things going against me. I need 4 pins that can be open collector and the 15V gate driver is much higher than the 3.8V (3.3V (Vcc) + 0.5V) maximum voltage rating per pin.
It appears that I am going to have to use gpio lines and bjt transistors to pull the gate voltage to ground. I was just wondering if I am misinterpreting the data sheet and I can in fact use the micro to pull the 15V gate to ground.
