Two-pin current source works at 400V for LEDs

Diodes Inc has created a family of two-pin constant current chips that can work at up to 400V.

Diodes-AL5890

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.


Leave a Reply

Your email address will not be published. Required fields are marked *

*