AL8807 (NRND)

Description

The AL8807 is a step-down DC/DC converter designed to drive LEDs with a constant current. The device can drive up to 8 LEDs, depending on the forward voltage of the LEDs, in series from a voltage source of 6V to 36V. Series connection of the LEDs provides identical LED currents resulting in uniform brightness and eliminating the need for ballast resistors. The AL8807 switches at frequency up to 1MHz. This allows the use of small size external components, hence minimizing the PCB area needed. Maximum output current of AL8807 is set via an external resistor connected between the V_IN and SET input pins. Dimming is achieved by applying either a DC voltage or a PWM signal at the CTRL input pin. An input voltage of 0.4V or lower at CTRL switches off the output MOSFET simplifying PWM dimming. It is available in SOT25 and the increased thermally capable MSOP-8EP.

Feature(s)

• MR16 lamps
• General illumination lamps
• 36V 1A LED drive capability - Drives up to 8 LED in series and provides cost effective solution for MR16 and other 12V AC/DC systems • 5% initial average LED current accuracy - Meets accuracy requirements of most lighting apps at cost effective price and improves inter-channel matching. • Simple digital PWM dimming with DC dimming on the CTRL pin - Provides flexible scheme to users with different dimming methods: DC for thermal control, PWM for brightness control • High switching frequency up to 1MHz - Reduces inductor value - reducing size of solution
• Small footprint packages with only 4 external components - High power density small PCB footprint solution

Application(s)

• MR16 lamps
• General illumination lamps