The LM3940IMP-3.3/NOPB is a 1A low-dropout Voltage Regulator, designed to provide 3.3V from a 5V supply. It is ideally suited for systems which contain both 5V and 3.3V logic, with prime power provided from a 5V bus. Because the LM3940IMP-3.3/NOPB is a true low-dropout regulator, it can hold its 3.3V output in regulation with input voltages as low as 4.5V. The LM3940IMP-3.3/NOPB means that in most applications the full 1A of load current can be delivered without using an additional heatsink.