The XB402U-27 is a cost efficient LED driver to drive low power LEDs. The advantages towards resistor biasing are:
• homogenous light output despite varying forward voltages in different LED strings
• homogenous light output of LEDs despite voltage drop across long supply lines
• homogenous light output independent from supply voltage variations
• longer lifetime of the LEDs due to reduced output current at higher temperatures (negative thermal coefficient)
The advantages towards discrete solutions are:
• lower assembly cost
• smaller form factor
• higher reliability due to less soldering joints
• higher output current accuracy due to pretested LED drivers
Dimming is possible by using an external digital transistor at the ground pin.
The XB402U-27 can be operated at higher supply voltages by putting LEDs between the supply voltage VS and the power supply pin of the LED driver. You can find further details in our application notes.
The XB402U-27 is a perfect fit for numerous low power LED applications by combining small form factor with low cost. These LED drivers offer several advantages to resistors like significantly higher current control at very low voltage drop ensuring high lifetime of LEDs.
