LM3940 IC - 1A - Low Dropout Regulator IC for 5V to 3.3V Conversion

The LM3940 is a 1-A low-dropout regulator designed to provide 3.3 V from a 5-V supply. The LM3940 is ideally suited for systems which contain both 5-V and 3.3-V logic, with prime power provided from a 5-V bus. Because the LM3940 is a true low dropout regulator, it can hold its 3.3-V output in regulation with input voltages as low as 4.5 V. The TO-220 package of the LM3940 means that in most applications the full 1 A of load current can be delivered without using an additional heat sink. The surface mount DDPAK/TO-263 package uses minimum board space, and gives excellent power dissipation capability when soldered to a copper plane on the PC board. Features:- Input Voltage Range: 4.5 V to 5.5 V Output Voltage Specified over Temperature Excellent Load Regulation Specified 1-A Output Current Requires only One External Component Built-in Protection against Excess Temperature Short-Circuit Protected Specification:- Parameter Specification Part number LM3940 Output options Fixed Output Iout (Max) (A) 1 Vin (Max) (V) 5.5 Vin (Min) (V) 4.5 Vout (Max) (V) 3.3 Vout (Min) (V) 3.3 Fixed output options (V) 3.3 Package Group DDPAK/TO-263 | 3, TO-220 | 3, SOT-223 | 4 Regulated outputs (#) 1 Operating temperature range ( C ) -40 to 125 Thermal resistance θJA (°C/W) 23 Noise (uVrms) 150 Rating See Data Sheet PSRR @ 100 KHz (dB) 32 Accuracy (%) 2.5 Dropout voltage (Vdo) (Typ) (mV) 310 Iq (Typ) (mA) 0.11 Package size: mm2:W x L (PKG) 3DDPAK/TO-263: 155 mm2: 15.24 x 10.16 (DDPAK/TO-263 | 3) 3TO-220: 47 mm2: 4.58 x 10.16 (TO-220 | 3) 4SOT-223: 46 mm2: 7 x 6.5 (SOT-223 | 4) Related Document:- LM3940 IC Data Sheet