Diodes Incorporated AL8843Q

Description

The AL8843Q is a hysteresis mode DC-DC step-down converter, designed for driving single or multiple series connected LEDs efficiently from a voltage source higher than the LED voltage. The device can operate from an input supply between 4.5V and 40V and provide an externally adjustable output current up to 3A. Depending upon supply voltage and external components, this converter can provide up to 60W of output power.The AL8843Q integrates the power switch and a high-side output current sensing circuit, which uses an external resistor to set the nominal average output current.Dimming can be realized by applying an external control signal to the CTRL Pin. The CTRL Pin will accept either a DC voltage signal or a PWM signal.The soft-start time can be adjusted by an external capacitor from the CTRL Pin to Ground. Applying a voltage of 0.3V or lower to the CTRL Pin will shut down the power switch.

Features

• Wide Input Voltage Range: 4.5V to 40V
• Output Current up to 3A
• Internal 40V NDMOS Switch
• Typical 4% Output Current Accuracy
• Single Pin for On/Off and Brightness Control by DC Voltage or PWM Signal
• Recommended Analog Dimming Range: 10% to 100%
• Soft-Start
• High Efficiency (Up to 97%)
• LED Short Protection
• Inherent Open-Circuit LED Protection
• Over Temperature Protection (OTP)
• Up to 1MHz Switching Frequency
• SO-8EP Packages Available in Green Molding Compound (No Br, Sb)

Typical applications

• Automotive Daytime Running Lights, Automotive Front and Rear Fog Lights, Automotive Turn/Stop Lights, Automotive Dimmable Interior Lights

More information

• Datasheet