I'm looking to integrate a LiPo charging circuit into my PCB, and found the
MCP7831 IC. It's got a
PROG pin, that allows you to change the behavior of the IC by use specific resistor values between that pin and ground.
But I'm wondering how it knows the value of the resistor?
I would think to know the value of the resistor your + voltage is applied to one side, and the other goes to an input pin of an IC that measures the lowered voltage. But if it connects straight to ground, how does the value get measured?