Fixed 8V LDO in SOT-223-4 — what it delivers
The Texas Instruments LM2940IMPX-8.0 is a fixed-output 8V positive LDO regulator rated for 1A continuous output current. It operates from an input up to 26V and delivers the regulated 8V rail with a maximum dropout of 1V at full load — enough headroom for a 9V battery or a lightly regulated 12V bus.
PSRR and protection — where it earns its keep
A PSRR of 66 dB at 120 Hz means the regulator attenuates 120 Hz ripple (full-wave rectifier residue) by a factor of about 2000 — useful for powering analog front-ends or sensor supplies where line-frequency noise couples into the signal chain. On-chip protection covers over-current, over-temperature, reverse polarity, and short-circuit conditions. The reverse polarity clamp is a practical safeguard when the input supply is field-wired or battery-connected and could be accidentally reversed.
The fixed 8V output is less common than the 5V or adjustable variants in the LM2940 family, which limits cross-reference options.