What the MAX16821BATI+ actually does
It is a controller, not a converter with integrated switches — meaning you supply the external MOSFET and inductor, and the chip handles the PWM dimming and regulation loop. The part supports three topologies — SEPIC, step-down (buck), and step-up (boost) — which gives a single BOM line the flexibility to drive LED strings in series or parallel depending on the input rail and output voltage needed. A higher frequency shrinks the magnetics but increases FET gate-drive loss; a lower frequency improves efficiency at the cost of a larger inductor. The single output drives an external N-channel MOSFET, and the PWM dimming input allows direct LED brightness control without an external DAC or microcontroller PWM pin. The supply voltage range spans 4.75 V to 28 V.
No stock or lead-time number is published here because the spot market moves daily; a quick RFQ will return the real picture.