The ISL9021AIRUMZ-T7A: ROHS3 compliant — the part meets the latest EU RoHS exemption-free standard, so it passes into European and UK supply chains without a compliance waiver.
250 mA LDO — dropout and quiescent current
Fixed 3 V output from a single LDO rated for 250 mA continuous — the dropout voltage is 0.25 V max at full load, so the input rail needs to stay above 3.25 V across load and temperature to keep the output in regulation. Quiescent current is 50 µA typical — the regulator's own draw is low enough for battery-powered designs where the load spends most of its time in a light or sleep state.
Protection set and package fit
Built-in protection covers over-current, over-temperature, reverse polarity, short circuit, and includes a soft-start ramp — the reverse-polarity clamp is unusual at this current level and saves an external Schottky on the input if the supply can reverse-bias. Packaged in a 6-UFDFN (1.6 x 1.6 mm) with a supplier device package of 6-UTDFN — the exposed pad on the underside carries the thermal path to the PCB copper, so the board footprint should include a thermal via array under the pad to keep junction temperature within the -40 to 85 °C operating range. Enable pin (active-high) lets the system power down the regulator to near-zero quiescent current when the load is idle — the pin threshold is compatible with 1.8 V logic, so a low-voltage GPIO can control it directly.