The LT3493EDCB#TRPBF comes in a 6-lead WFDFN with exposed pad (2x3 mm DFN). The 750 kHz fixed switching frequency keeps the inductor small (typically 10-22 µH for this current range) but pushes the switch-node ringing above 30 MHz — layout must keep the input cap, inductor, and catch diode loop tight to avoid radiated emissions.
Input range and output flexibility
This is a non-synchronous buck — the low-side catch diode is external. The 3.6 V minimum input means it starts from a 5 V rail with margin, or from a 12 V battery sitting at 10 V under crank. The 36 V maximum covers 24 V industrial rails and 12 V load-dump transients without an external clamp. Output adjusts from 0.78 V up to 34.2 V via a resistor divider on the FB pin. The 0.78 V reference lets it power 1.2 V core rails and 3.3 V I/O from the same BOM — just change the feedback resistor pair.
At the hot end, the 1.2 A output must be derated per the junction temperature — the WFDFN's thermal resistance means full current is only available below roughly 60°C ambient unless airflow or a larger copper area is used. The 750 kHz switching frequency is fixed — no frequency foldback or spread-spectrum. At light loads, the part pulses in Burst Mode to maintain efficiency, which introduces ripple at the audio band. If the load is always below 100 mA, a linear regulator may be quieter.
