I'm planning to use a set of daisy chained 74HC595s to control a set of 108 mosfets, 3 of them are geographically in the same area (couple of mm apart) and for the sake of modularity should each use their own register. That would mean I will use 36 74HC595s and chain them together. They are all on one board and the distance between the groups of 3 is around 2-5cm.
- How do I calculate the minimum time it takes to to write the whole set of serial instructions to 36 74HC595? I figured I need to add clock rise times and propagation times, but I'm not sure exactly how.
- Is there anything else I need to add for this to work? Do I need additonal buffers or delay components? There's gonna be some noise made by high currents (through the mosfet).