Diodes AL8400 linear LED driver controller

The AL8400 linear LED driver controller from Diodes has been designed to tightly regulate a wide variation of high-brightness LED currents via an external transistor.

Suiting a broad range of LED chains in illumination, indication or signage systems, the controller can directly operate from 2.2 to 18 V and will drive either N-channel MOSFET or NPN bipolar transistors.

The driver has a low 200 mV current sense voltage which reduces operating voltage overheads and increases efficiency compared with traditional devices.

Its open collector output drives the external pass transistor allowing it to regulate LED currents from tens of mA to above one amp.

Using an external pass transistor allows power dissipation and maximum drive capability to be optimised. Longer LED chains needing significantly more than 18 V can be driven with minimal additional external components.

The device’s low temperature drift and 3% reference voltage at 25°C outperforms most existing linear solutions while keeping BOM costs down at the same time. The driver in its small-footprint, low-profile SOT353 package delivers good power density with low EMI.