Adjustable 1.5A linear regulator in SOT-223-4
The LM317AEMPX is a positive adjustable linear voltage regulator from Texas Instruments, delivering up to 1.5A output current with an input range up to 40V and an adjustable output from 1.25V to 37V.
PSRR and load regulation for analog rails
With a PSRR of 80dB to 65dB at 120Hz, this regulator provides meaningful ripple rejection for powering sensitive analog circuits — op-amp supplies, ADC reference buffers, or sensor front-ends — where line-frequency ripple from a rectified mains supply would otherwise couple into the signal path. The 10 mA quiescent current is typical for a 1.5A-capable linear regulator; it is not a low-Iq part for battery operation, but the trade-off buys better transient response and output noise performance than a switching regulator at this load level.
NRND — plan the transition
That means existing production runs and BOM lines can still be filled through the independent distribution channel, but new designs should migrate to a current-production alternative — typically another LM317-family variant in the same SOT-223-4 footprint.
SOT-223-4 footprint and thermal layout
The SOT-223-4 package (also designated TO-261-4, TO-261AA) is a surface-mount medium-power package. For 1.5A operation at higher input-output differentials, a minimum of 1 in² of 2-oz copper on the top layer is typical to keep the junction below 125°C. The package is supplied in Tape & Reel, ready for automated pick-and-place.