300 mA LDO with dual-mode output
The MAX8860EUA33+ is a positive-output linear regulator delivering 300 mA from a single LDO channel. It ships with a fixed 3.3 V output but can be configured as adjustable down to 1.25 V via external resistors — one device covers both a dedicated 3.3 V rail and a generic low-voltage supply on the same BOM line.
Dropout and quiescent budget
Maximum dropout is 155 mV at the full 300 mA load (typical), which means the input rail needs only 3.455 V to maintain regulation on the 3.3 V output — a 5 V rail with a Schottky diode drop still has margin. The 270 µA quiescent current (Iq) sets the standing power draw; in a battery-powered sensor waking once per second, the regulator's own consumption dominates the sleep budget more than the load. Input voltage range extends to 6.5 V max, so the part runs comfortably from a 5 V ±10 % supply or a single Li-ion cell. The 6.5 V output maximum (adjustable mode) mirrors the input ceiling — the pass FET saturates before the output can exceed the input.
Protection and control interface
On-chip protection covers over-temperature, reverse polarity, and short-circuit events — the regulator shuts down before the junction exceeds the die rating, and the reverse-polarity clamp prevents damage if the input is accidentally reversed. The enable pin allows the regulator to be gated by a GPIO or a power-good signal from an upstream converter; the fault output (active-low open-drain) asserts when the output drops out of regulation, which can drive a reset line or a status LED.
Housed in the 8-uMAX/uSOP package (3.00 mm width, 0.118" pitch), the part is a surface-mount fit for compact PCBs.