50 mA, 4-60 V input — Himalaya buck in a 3x2 mm TDFN
The MAX17551ATB+T is a step-down (buck) switching regulator from the Analog Devices Himalaya family, delivering up to 50 mA from a 4 V to 60 V input rail. Output voltage is adjustable from 0.8 V up to 54 V via an external resistor divider, and the part uses synchronous rectification — the internal low-side FET replaces the usual catch diode, which keeps efficiency above 85 % across most of the load range and eliminates the external Schottky from the BOM. The switching frequency is programmable from 100 kHz to 2.2 MHz via a single resistor. A 400 kHz setting keeps the inductor small while staying clear of AM-band noise; 2.2 MHz pushes the switching harmonics above the EMI compliance band for sensitive receiver front-ends.
Package and board-fit — 10-TDFN with exposed pad
The 3x2 mm footprint suits space-constrained designs on 2-layer boards; the paddle's thermal vias should connect to an inner ground plane for heat spreading.
Lifecycle and compliance — active, ROHS3, no second-source
The Himalaya series includes higher-current siblings, but none are pin-compatible with this 10-TDFN layout; a board spin would be required for a different current rating.