The AL8843Q and AL8862Q buck converters are designed for driving single LEDs and multiple LED strings in and around vehicles. Applications include daytime running lights (DRL), fog lights, indicators and brake lights. 

Supply voltage is 4.5 to 40V for the AL8843Q and 5.0 to 55V for the AL8862Q. Both can withstand even severe voltage variations, such as load dumps during low cranking or stop-start operation, without suffering any corresponding degradation in the LED drive current, says the company.

Both parts have an integrated power MOSFET - 40V/0.2Ω for the AL8843Q and 55V/0.4Ω for the AL8862Q. Both drivers also have hysteretic-mode buck LED driver control, which simplifies the feedback loop. This allows engineers to realise highly stable buck converter designs using just four external components, says Diodes. Output current is 3A for the AL8843Q and up to 1A for the AL8862Q. Both parts support full scale (0 to 100%) PWM dimming, controlled with either an analogue input between 0.4 and 2.5V or a PWM signal generated by an external microcontroller or host processor. Safety features include over-temperature protection as well as LED short- and open-circuit protection. The AL8862Q incorporates an open-drain fault indication pin, which is asserted low to report faulty conditions.

The AL8843Q and AL8862Q in SO-8EP are qualified to AEC-Q100 Grade 1, support PPAP documents, and are manufactured in IATF16949 certified facilities.

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