25 A from a 6x6 mm QFN — the thermal reality
The MAX8686ETL+ is a synchronous step-down regulator that delivers 25 A continuous from a 40-TQFN package measuring 6x6 mm. Without adequate copper area and airflow, the junction will hit the +85°C operating ceiling well before the load reaches 25 A.
Input rails and output range
Input voltage spans 4.5 V to 20 V, so it runs off a regulated 5 V rail, a 12 V intermediate bus, or a loosely regulated supply up to 20 V. Switching frequency is programmable from 300 kHz to 1 MHz. Lower frequencies reduce switching losses and improve efficiency at high input voltage; higher frequencies shrink the inductor and output capacitor but increase FET switching loss. The trade is set by a single resistor to ground.
The part ships in bulk (tray or tube), not tape-and-reel, so plan for manual or tray-fed pick-and-place. ROHS3 compliant, no lead-exemption, standard Pb-free reflow profile.
No official successor or second-source cross-reference is published.