LM2940T-5Fixed +5 V low-dropout regulator

LM2940T-5 is a three-terminal regulator that produces a nominal +5 V output from a higher positive DC source. This page selects LM2940CT-5.0/NOPB in TO-220 and LM2940CS-5.0/NOPB in its surface-mount package. The internal reference, feedback amplifier and series pass device form the voltage-control loop. The LM2940C uses a low-dropout pass stage, but its output capacitor is part of the stability design. Use at least 22 µF effective capacitance with ESR in the manufacturer’s permitted range across load and temperature. An arbitrary low-ESR ceramic substitution can oscillate. The illustrated +7.5 V-to-+5 V supply drives a 50 Ω load at approximately 100 mA. The load dissipates 0.50 W and the pass stage loses about 0.25 W before ground-current losses. All package views follow the selected part; the example is a DC circuit reference, not a live simulation.