On Fri, May 13, 2022 at 05:33 PM, Robert Benward wrote:

Those 5161 are strange beasts.  The external MOSFETS are on a board below and I suspect the chip output is being used to driver the gates of the mosfets, but since the upper board is available alone, I don't know how they break the pin-to-socket-to-pin connection to route the outputs to the gate inputs.  The Fysetc wiki shows the upper boards as available separately.  The upper board alone can handle 3.5A.   I wonder where the power board comes from

AFAIK the MOSFETs of TMC5161's are on-die where the TMC5160 has the MOSFETs off-die and that is the only difference.

Thinking the second board they plug into is one of these basically:
https://learn.watterott.com/silentstepstick/protector/