Good evening,
I've spent all day studying how MOSFETs work, in particular P-Channel Logic Level MOSFETs. I understand how these work even down to the internal construction and how the P-Channels use holes to flow the power from drain to source. What I just can't come to terms with it how to calculate what voltage I need to apply to the Base to toggle the MOSFET on and off. Like I have said, I have spent all day on MOSFETs and I'm really struggling and its starting to slowly eat away at me now, frustrated itsn't the best description for my emotions right now, it must be admitted.
I'm planning on powering the base through a MCU, at the moment i have it powering with 3v3 but i could change that to 5v if it means having a 5v output is more desirable. Lets take for example the NX3008PBKW P Channel MOSFET. Datasheet is here.
All that I know from here is that my circuitry needs to have a pull-up resistor on the base to make sure the base is not left floating while the MCU boots/is disconnected for some reason. I also know that the load is to be placed in between the source and ground and that the drain is connected to 5v.
This is now where I'm now lost. I'm not asking for someone to do this for me, I'm here to learn. I need to learn the process on how to calculate what is needed and why it is needed to be that value.
If you need to know the load current, its 65mA. The load is a simple PIR motion detection module, datasheet is here.
If there is any more information you require, please ask away. I'm very eager to learn this process but please bare with me as I've been studying it for the past 12 hours and i'm just struggling on this section now. I feel rather pathetic with taking this long but her, we all start somewhere...
Thanks, Sam.
I've spent all day studying how MOSFETs work, in particular P-Channel Logic Level MOSFETs. I understand how these work even down to the internal construction and how the P-Channels use holes to flow the power from drain to source. What I just can't come to terms with it how to calculate what voltage I need to apply to the Base to toggle the MOSFET on and off. Like I have said, I have spent all day on MOSFETs and I'm really struggling and its starting to slowly eat away at me now, frustrated itsn't the best description for my emotions right now, it must be admitted.
I'm planning on powering the base through a MCU, at the moment i have it powering with 3v3 but i could change that to 5v if it means having a 5v output is more desirable. Lets take for example the NX3008PBKW P Channel MOSFET. Datasheet is here.
All that I know from here is that my circuitry needs to have a pull-up resistor on the base to make sure the base is not left floating while the MCU boots/is disconnected for some reason. I also know that the load is to be placed in between the source and ground and that the drain is connected to 5v.
This is now where I'm now lost. I'm not asking for someone to do this for me, I'm here to learn. I need to learn the process on how to calculate what is needed and why it is needed to be that value.
If you need to know the load current, its 65mA. The load is a simple PIR motion detection module, datasheet is here.
If there is any more information you require, please ask away. I'm very eager to learn this process but please bare with me as I've been studying it for the past 12 hours and i'm just struggling on this section now. I feel rather pathetic with taking this long but her, we all start somewhere...
Thanks, Sam.