Here is an app note from Microchip describing how a PIC12HV615 MCU can be used to implement a digital current control loop for power LEDs:
This document describes a power LED driver solution using the PIC12HV615 microcontroller (MCU). The PIC12HV615 is an 8-pin MCU with many integrated analog features. The LED driver circuit is a buck (stepdown) solution and the circuit presented here can operate from most any input voltage source as long as it exceeds the forward voltage of the LEDs to be driven.
Thanks, this is someothing I’m investigating at the minute!
I was wondering about building a “micro-bench” PSU with voltage / current control (from USB / serial) up to 5V / 900mA, as supplied by a USB3 port. Something with high efficiency components that would sit comfortably in a tiny USB module, say the size of a USB soundcard.
Probably loads of applications for this but for me, this would be ideal to drive some LEDs in current mode rather than PWM (usually around 3.1V, 0 to 1A) for microscopy.