L78M05CDT-TR

L78M05CDT-TR is the DPAK (TO-252) tape-and-reel ordering code for the STMicroelectronics L78M05 — the 0.5 A M-grade member of the L78 family, a fixed 5 V positive linear regulator with internal thermal overload and short-circuit protection. The M grade is the selection point and the common ordering mistake: this code is a 500 mA device, not the 1.5 A standard L7805 sold under other codes in this family, so a BOM line that simply says '7805' is under-specified — confirm the load current fits the M grade before approving it. In return the DPAK footprint is far smaller than D2PAK or TO-220, which is exactly right for the distributed 5 V point-of-load rails in control boards, metering and appliance electronics where each rail draws a few hundred milliamps. The C grade denotes the standard commercial output tolerance selection of this family. Selection advice: the DPAK tab solders to board copper as its only heatsink, so compute (VIN − 5 V) × IOUT against the copper area you actually have; if the rail must deliver close to 0.5 A from a 12 V input continuously, step up to the 1.5 A D2PAK code instead of relying on this smaller package. Match the full L78M05CDT-TR code for grade, package and reel packing. Parameters verified against STMicroelectronics documentation.