AL8841Q Automotive Buck LED Drivers

Diodes' AL8841Q is a hysteretic-mode DC/DC step-down LED driver that is designed for driving single or multiple series-connected LEDs efficiently from a voltage source higher than the LED voltage. The device operates from an input supply between 4.5 V and 40 V, and provides an externally adjustable output current of up to 1 A for the TSOT25 and 1.5 A for the MSOP-8EP packages. The AL8841Q integrates the power switch using an external resistor to set the LED current. It provides a simple and small footprint solution using a minimum of four external components.

The CTRL pin accepts a DC analog voltage signal or a PWM digital signal to provide a simple way of adjusting LED brightness. The CTRL pin can also be used to adjust the AL8841Q’s soft-start time and can be adjusted using an external capacitor between the CTRL and ground. A voltage of 0.3 V or lower to the CTRL pin stops the switching but does not place the device into a low-power standby state, thereby providing a faster PWM dimming response than the AL8860Q/61Q.The AL8841Q is available in a thermally-enhanced MSOP-8EP package and a small-footprint TSOT25 package.