LM1117MPX-ADJ/NOPB (TEXAS INSTRUMENTS)

The LM1117MPX-ADJ/NOPB is a low-dropout Linear Voltage Regulator with a dropout of 1.2V at 800mA of load current. The LM1117 is available in an adjustable version, which can set the output voltage from 1.25 to 13.8V with only two external resistors. The LM1117 offers current limiting and thermal shutdown. Its circuit includes a Zener trimmed band-gap reference to assure output voltage accuracy to within ±1%. A minimum of 10µF tantalum capacitor is required at the output to improve the transient response and stability The LM1117 adjustable version develops a 1.25V reference voltage VREF between the output and the adjust terminal. The current IADJ from the adjust terminal could introduce error to the output. But since it is very small compared with the I1 and very constant with line and load changes, the error can be ignored. The constant current I1 then flows through the output set resistor R2 and sets the output voltage to the desired level.