[Leo] solved both problems by using two of the three PWM channels on the chip in concert — one to control the current and one to PWM the LED. The circuit he came up with is deceptively simple ...

In his video [Afroman] describes how the LM317 can be used to regulate current rather than voltage ... driving LEDs and laser diodes. While this circuit may not be as efficient as an LED driver ...

The IS31FL3758 supports a configurable matrix ranging from 48 channels (48ch) up to a 40×9 matrix, consisting of 48 constant current sinks and 9 ... and a built-in de-ghosting circuit to eliminate LED ...