So, I have an external ADC, and external 5V source (pull up) and an external ground. I need to switch between different resistors on this signal without using my PIC's ground. That is, I need to force the signal through a resistor in order to change the voltage the ADC sees, but have to use an external ground.
Here is an idea I thought up. I'm not certain this is a job for a regular NPN or mosfet. The source pullup is 1K so this isn't a lot of current.
Is there a cleaner way to do this? I don't want to ground the resistors right to me because the external ground may be a lot cleaner.
Any thoughts?
Here is an idea I thought up. I'm not certain this is a job for a regular NPN or mosfet. The source pullup is 1K so this isn't a lot of current.
Is there a cleaner way to do this? I don't want to ground the resistors right to me because the external ground may be a lot cleaner.
Any thoughts?