A simple 2-pin constant current LED driver from Diodes Inc. can handle a DC input up to 400 V. The AL5890 is available in pre-fixed regulated current ratings of 10, 15, 20, 30 and 40 mA. It supports either high-side or low-side driving and is intended for use with LED lighting chains.
 
The simple 2-pin design allows easy operation of LED strips at high DC voltages without the need for any additional resistors or components. The chips are designed for operation with DC supplies up to 400 V making them suitable for use with rectified AC supply up to 230 V. Note: An earlier version of the data sheet incorrectly indicated a dielectric strength of 500 VDC.
 
The AL5890 turns on when the voltage difference between the IN and OUT pin is greater than 7 V. The constant current accuracy is ± 2 mA and the working temperature range is -40 to +105 °C. For higher power requirements two or more AL5890 devices can simply be connected in parallel. The chips contain a power transistor, bandgap reference and control electronics.
 
To optimize heat dissipation for various LED lighting applications the regulator is manufactured in PowerDI123, SOT89-3L and TO252-3L thermally enhanced package. Thermal resistance for the junction to ambient of the PowerDI123 (Type B) 3.70 x 1.78 mm version is about 76 °C/W. Internal thermal foldback protection reduces the current at high operating temperatures.