Synchronous buck controller for 4V to 38V rails
The LTC3867EUF#PBF is a single-phase synchronous step-down DC/DC controller from Analog Devices, designed to drive external N-channel MOSFETs. It accepts a 4V to 38V supply and delivers a regulated positive output via a transistor driver. The switching frequency is programmable from 200kHz to 1.2MHz, letting you trade inductor size against efficiency. Control features include current limit, enable, frequency control, power-good flag, soft start, and tracking — enough for sequenced power-up in multi-rail systems. The 24-QFN (4x4 mm) package with exposed pad handles the thermal load. Typical applications are intermediate bus conversion, industrial power supplies, and automotive-grade point-of-load regulators where the -40°C to 125°C junction temperature range is needed.
What the switching frequency range means for the BOM
A 200kHz to 1.2MHz programmable range gives the designer a real choice: run at the low end for best efficiency and wider inductor saturation margin, or push toward 1.2MHz to shrink the inductor footprint and reduce output capacitor count. The 98% maximum duty cycle supports high step-down ratios without dropout issues. Synchronous rectification is built in, so external Schottky catch diodes are unnecessary — that saves board area and BOM cost.
Lifecycle and sourcing posture
ROHS3 compliant. For volume BOM lines, this part is sourced through independent distribution and quoted to order against an RFQ. No LTB risk on the horizon.