5V rail for breadboards and beyond
The Texas Instruments LM78M05CH is a fixed 5V positive linear regulator delivering up to 500 mA — the classic 78xx-series workhorse in a TO-39 metal can. That 5V output is the standard logic and microcontroller rail, so this part fits right into powering an Arduino-clone brain or a small sensor array on a perfboard. With a 35V maximum input, it can take a 12V wall wart or a 24V industrial supply and drop it cleanly to 5V, as long as the power dissipation stays within the package limits. The 3 mA quiescent current means it's not the leanest choice for battery gear that sleeps for months, but for a bench supply or a always-on control board it's perfectly fine.
What the ratings mean on your bench
The 78 dB PSRR at 120 Hz tells you this regulator rejects ripple from a full-wave rectified supply — that's the 100/120 Hz hum from a transformer + bridge rectifier. If you're feeding a sensitive analog front-end or an audio circuit, that 78 dB of rejection keeps the mains buzz out of your signal. It's not the highest PSRR in the class (some LDOs hit 90 dB), but it's solid for a general-purpose part. The TO-39 metal can helps conduct heat away — bolt it to a small heatsink if you're pulling close to the full 500 mA from a high input voltage. Built-in over-current, over-temperature, and short-circuit protection mean you don't need external crowbar circuits or fuses for basic fault handling. If you accidentally short the output with a probe, the regulator survives and recovers when the short is removed.
Through-hole and hand-solderable
The TO-205AD / TO-39-3 metal can is a through-hole package with three leads — input, ground, output. It's easy to solder into a perfboard or a prototype PCB without a hot-air station. The metal tab is the ground plane and also the thermal path; soldering it to a copper pour helps with heat sinking. Supplied in bulk (not tape-and-reel), so it's ideal for small-batch builds and one-off projects where you're not feeding a pick-and-place machine.
ROHS3 compliant, so it meets the latest EU restriction on hazardous substances. No special handling or exemption paperwork needed for shipping into regulated markets.