Active production — stable sourcing for 12V rail designs
The L4940D2T12-TR: Sourced per RFQ through standard distribution; no stock-holding claim, but the lifecycle posture means lead times should track normal production runs.
Dropout headroom and PSRR for post-rectifier rails
Maximum dropout voltage is 0.9 V at 1.5 A output — that sets the minimum pre-regulator voltage. The 17 V input maximum gives some transient headroom on a 12 V bus. PSRR is 61 dB at 120 Hz, which is the line-frequency ripple rejection you get after a bridge rectifier. That figure drops at higher frequencies, so for switching-noise rejection you will want additional post-filtering or a second-stage LDO. The fixed 12 V output eliminates the feedback divider noise that an adjustable regulator would inject.
Protection set and thermal envelope
Built-in protection covers over-temperature, reverse polarity, and short circuit. Quiescent current is 8 mA typical; the maximum supply current is 50 mA.
D2PAK footprint and mounting
Surface-mount D2PAK (TO-263-3) with two leads plus the tab.