300mA LDO with 70dB PSRR — what that means for a clean rail
The Toshiba TCR3DG18,LF is a 300mA fixed-output LDO regulator in the TCR3DG series, delivering a regulated 1.8V rail from an input up to 5.5V. Its 70dB PSRR at 1kHz means that ripple on the input — say from a switching converter upstream — is attenuated by a factor of about 3000 before it reaches the load. That matters when you are feeding a noise-sensitive analog front-end or a PLL that jitters on supply hash. The dropout voltage max is 365mV at the full 300mA load, so the input rail needs to stay above roughly 2.165V to keep the output in regulation under worst-case conditions.
Package, footprint, and field-swap reality
Housed in a 4-WCSPE package (0.65x0.65mm), this is a tiny ball-grid array — not something you swap with a soldering iron in the field. It is a reflow-only part, and the 0.65mm pitch means the board layout needs a stencil and a proper reflow profile. The enable pin (Control Features: Enable) lets you shut the output down to near-zero quiescent current for power sequencing or sleep modes. Protection includes inrush current limiting, over-current, and over-temperature shutdown — so it survives a momentary short on the output without letting the smoke out.
RoHS compliant, so it passes the standard environmental requirements for EU and most global markets.