8V fixed output, 1A capacity — the rail it serves
The Texas Instruments LM2940S-8.0 is a fixed 8V output, 1A low-dropout positive voltage regulator in a DDPAK/TO-263-3 surface-mount package. It is a single-output LDO designed for applications that need a regulated 8V rail from a higher, unregulated DC input — common in automotive electronics, industrial control boards, and post-regulation stages in multi-rail supplies.
The maximum dropout voltage is 1V at 1A output current. This means the input must stay above 9V to maintain regulation at full load — a 9V nominal rail is the practical floor, and a 12V automotive battery bus gives comfortable margin even during cranking. PSRR is 66 dB at 120 Hz, which is the dominant ripple frequency from a full-wave rectified mains supply. This level of rejection cleans up the residual AC ripple on the input before it reaches the load — relevant when this regulator feeds an analog front-end or a sensor bias rail.
Protection set and temperature range
The regulator includes over-current, over-temperature, reverse polarity, and short-circuit protection. These protections make it suitable for environments where the input supply is noisy or subject to fault conditions — automotive load-dump, reverse battery, or a shorted load on the output.
No official successor or replacement part number is recorded in the lifecycle data.