Electronics Weekly
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.
