and you can’t usually obtain such peak currents from the microcontroller port. This Design Idea describes “Chipiplexing,” a method in which you need to add only N cheap, bipolar transistors. This ...

A simple op-amp, and pnp transistor or p-channel mosfet in the positive rail (example right), was the obvious answer to me, but what had other people done? One internet search later and, aside from ...