300 mA LDO, 70 dB PSRR — the noise floor decision
The MIC5364-3.3YMT-T5 is a fixed 3.3 V output LDO regulator rated for 300 mA continuous output current, housed in the 6-TMLF (1.2x1.2) package. Its 70 dB PSRR at 1 kHz means the regulator attenuates upstream switching noise by a factor of 3,000 — a 10 mV ripple on the input rail becomes roughly 3 µV at the output, which is clean enough to power a 16-bit ADC reference without a post-filter. Dropout voltage is 0.38 V max at the full 300 mA load, so the input rail needs to stay above 3.68 V to keep the output in regulation.
Industrial temp grade and quiescent draw
The -40°C to +125°C operating range qualifies the part for under-hood automotive and outdoor industrial enclosures where the ambient temperature cycles past 85°C. Quiescent current is 53 µA typical, rising to 70 µA max — low enough that the regulator's own draw does not dominate the sleep budget in a battery-powered sensor node that spends most of its life in shutdown. Enable control lets the system processor gate the regulator output, cutting the load current to near zero during standby. Protection features include over-current and over-temperature shutdown — the part folds back rather than latching, so a temporary short on the output clears without a power cycle.
The 6-TMLF package is a 1.2x1.2 mm body with an exposed thermal pad. The pad should be soldered to a PCB copper plane for thermal dissipation — the RthJA drops significantly with a 1-inch-square pad on a two-layer board. The part is also available in cut tape (CT) for prototyping quantities.