Diodes AL5801 linear LED driver

Needing only two additional components, the AL5801 linear LED driver enables designers to simplify motor vehicle interior, signage and general lighting control circuits.

Integrating a 100 V-rated N-channel MOSFET with a pre-biased NPN transistor, this small footprint SOT26 packaged device will drive chains of up to 30 low-power, series-connected LEDs with currents from 20 to 350 mA.

The device’s open-drain output operates between 1.1 and 100 V, ensuring common 12, 24 and 48 V power rails are supported, while the LED current is set using an external low-value resistor.

By generating a 0.56 V reference voltage across the resistor, the driver’s internal control transistor helps minimise power losses and ensures a sufficient supply voltage margin.

Due to the reference voltage’s negative temperature coefficient, the output current is automatically reduced at higher temperatures, helping to protect the LED chain from any damage. In addition, its wide operating temperature range of -40 to +150°C means it can be mounted immediately adjacent to LEDs where PCB space is limited.