Two-pin current source works at 400V for LEDs


Intended to control strings of LEDs running direct from rectifier mains, and called AL5890, it is available 10mA, 15mA, 20mA, 30mA, and 40mA variants

“Its simple two-pin design means it can be inserted directly in the LED string in low-side ac or dc, or high-side ac or dc linear configurations without any external resistors. It is designed to tolerate dc voltages of up to 400V and can be used in off-line applications up to 230Vac. Note: an early version of the data sheet incorrectly states 500Vdc operation.

Necessary forward voltage for full regulation is 7Vmax.

Overall accuracy is better than ±2.0mAtyp and the divices work over -40 to +105°C, said the firm.

For more current, multiple devices can be paralleled.

Inside is a power transistor, bandgap reference and both voltage and current control circuits.

To address heat dissipation in different LED lighting applications, packaging options include PDI123, SOT89-3L and TO252-3L.

Junction to ambient is 75.84°C/W in the 3.7 x 2.8mm PDI123 version.

Thermal fold-back protection is included, reducing current at high operating temperatures.

Applications are expected in LED lamps, commercial LED fixtures, emergency lighting, signage and down-lights, as well as decorative and architectural lighting.

Email: HK TEL: +00 852-30522530 ADD: Flat/Rm A17 9/F, Silvercorp International Tower 707-713 Nathan Road MongKok, Hong Kong.