The IS31FL3728-QFLS3-TR from Lumissil Microsystems is a LED Driver IC with Input Voltage 2.7 to 5.5 V, Output Current 42.3 to 42.8 mA, Operating Temperature Range -40 to 105 Degree C. Tags: Surface Mount, General Purpose LED Driver. More details for IS31FL3728-QFLS3-TR can be seen below.