...
http://ww1.microchip.com/downloads/en/DeviceDoc/AT9917-Automotive-LED-Driver-IC-with-High-Current-Accuracy-Data-Sheet-20005557A.pdf (larger, boost, but very complex)
https://www.diodes.com/assets/Datasheets/BCR420UW6Q-BCR421UW6Q.pdf (very simple, linear, slightly easier to solder than first option)