/diy/ - Do It Yourself

>>1549862
it gets tied in with the other grounds, at a specific point, preferably at the power inlet of the board or some other point that doesn't bounce much. it's the same principle as a Kelvin connection: one connection for current, one for voltage. power ground carries all the current in the system, AGND ideally carries none. here's a shitty sketch. the idea is that current flowing to other loads through the ground plane, whose resistance is small but not zero, won't skew the reference zero input of the TC amp with respect to the reference zero input of the MCU, and therefore won't skew the measurement
(assuming the MCU has a differential input and/or a voltage reference that is set with respect to AGND)