4.2 V fixed LDO in SOT-553 — the noise-sensitive rail choice
The Toshiba TCR2EE42,LM(CT is a single-output positive fixed LDO regulator delivering 4.2 V at up to 200 mA from a SOT-553 package. Its 73 dB PSRR at 1 kHz makes it a candidate for powering analog or RF sections where supply ripple rejection matters, not just a generic digital rail.
Dropout and headroom at 150 mA
Maximum dropout is 200 mV at 150 mA, so a 4.4 V input keeps the output in regulation at that load. With a 5.5 V absolute maximum input, the part tolerates a 5 V rail with margin. The 60 µA quiescent current is moderate — not micro-power, but acceptable for always-on blocks in industrial or telecom gear where the load current dominates the power budget.
The SOT-553 footprint is compact — about 1.6 mm × 1.6 mm — which helps on dense PCBs but limits thermal dissipation; at 200 mA continuous with 1 V drop, the junction rise is roughly 60°C above ambient in still air, so the 85°C ambient cap is real.
Listed as Active, so no last-time-buy pressure for production builds. The TCR2EE series is current. Note RoHS non-compliance — verify your assembly line's exemption allowance or plan for a lead-free alternative.