20 mA LDO with 4.5 µA quiescent current
The MAX1725EUK is a positive-output adjustable linear regulator delivering up to 20 mA from a 1.5V to 5V output range, with a maximum input of 12V. Maximum dropout is 0.6V at the full 20 mA load, so the input rail needs to stay at least 600 mV above the target output voltage across temperature and load. That headroom is manageable from a 3.6V Li-ion cell feeding a 3.0V output, but tightens if the battery sags near end-of-discharge.
Protection set and operating range
On-chip protection covers overcurrent, overtemperature, reverse polarity, and short circuit — four failure modes that commonly kill an unprotected LDO in field-replaceable or user-connected equipment. The enable pin (active-high) lets a system controller gate the regulator output, cutting the load current to near-zero in deep-sleep states. The SOT-23-5 package (SC-74A) is a standard surface-mount footprint with good thermal dissipation for the 20 mA current level — junction-to-ambient thermal resistance is typically in the 250-300°C/W range for this package, so at 20 mA with a 5V dropout the self-heating is under 10°C.
No official pin-compatible second source is documented, but the SOT-23-5 footprint is widely used across the industry; a parametric cross-reference to a similar LDO from another vendor is feasible at the board-layout level if supply tightens.