1.5 A LDO with 0.38 V dropout — the headroom decision
The LP3852ET-3.3/NOPB is a 1.5 A positive fixed-output LDO from Texas Instruments, delivering 3.3 V from a maximum input of 7 V. That 0.38 V ceiling is the number to budget for worst-case headroom — not the typical figure — and it sets the minimum input voltage for the design.
PSRR 73 dB to 57 dB at 120 Hz — ripple rejection across the line
Power-supply rejection ratio is specified at 73 dB to 57 dB at 120 Hz, which is the full-wave rectifier ripple frequency. The 73 dB figure applies at lower dropout headroom; as the input-to-output differential narrows, PSRR drops toward 57 dB.
Through-hole TO-220-5 — thermal and board-fit
The TO-220-5 formed-leads package (supplier device package TO-220-5) is a through-hole power package. The formed leads are spaced for standard 0.100-inch pitch holes.