Active 4 A non-synchronous buck
The LT3690IUFE#PBF is an active-production step-down (buck) regulator from Analog Devices, rated for a continuous 4 A output current — the highest in this non-synchronous family of adjustable switchers. Its 3.9 V to 36 V input range covers common industrial, automotive, and battery rails, and the adjustable output (0.8 V to 20 V) lets a single design serve core and I/O voltages without a second regulator.
Switching frequency and thermal envelope
The switching frequency can be set from 138 kHz to 1.5 MHz — lower frequencies improve efficiency but require a larger inductor; higher frequencies shrink the magnetics at the cost of increased switching losses. Because it uses an external Schottky diode (non-synchronous topology), the BOM includes one extra component and the thermal layout must account for diode conduction losses — the trade-off is lower cost and no risk of cross-conduction at light loads.
Package and compliance
Supplied in a tube, the LT3690IUFE#PBF is housed in a 26-WFQFN exposed pad package (26-QFN, 4x6 mm) for surface-mount assembly — the pad must be connected to the ground plane for rated thermal performance. ROHS3 compliant, with no lead, mercury, cadmium, or other restricted substances — suitable for EU and global markets without exemption tracking.