5V rail regulator – 1.5A output and dropout headroom
The L7805ACV-DG is a fixed 5V output positive linear regulator from STMicroelectronics, rated for 1.5A continuous output current. The 2V typical dropout at 1A means the input rail must stay above 7V to hold regulation under full load — a standard headroom requirement for 78xx-family parts.
Ripple rejection and thermal envelope
PSRR is specified at 68 dB at 120 Hz — this is the ripple-rejection figure that matters when the regulator follows a full-wave rectifier or a switching preregulator. The operating temperature range from 0°C to 125°C covers most commercial and industrial environments; the TO-220 package with a heatsink can dissipate the thermal load of a 1.5A rail, provided the input-output differential is kept within the power-dissipation budget.
Protection features and quiescent draw
Built-in over-temperature and short-circuit protection are included on-chip — the regulator shuts down before the junction exceeds the safe limit. Quiescent current is 6 mA typical, which is negligible for most loads but worth noting in always-on or battery-backed rails where the idle draw adds up.