
LM3940 1-A Low-Dropout Regulator
A true low dropout regulator providing 3.3V from a 5V supply
- 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
- Package Group: DDPAK/TO-263, TO-220, SOT-223
Top Features:
- Input Voltage Range: 4.5V to 5.5V
- Output Voltage Specified over Temperature
- Requires only One External Component
- Built-in Protection against Excess Temperature
The LM3940 is ideally suited for systems with both 5V and 3.3V logic, offering a true low dropout regulator that maintains 3.3V output even with input voltages as low as 4.5V. The TO-220 package allows for full 1A load current delivery without additional heat sink requirements, while the surface mount DDPAK/TO-263 package offers minimal board space usage and excellent power dissipation when soldered to a copper plane.
Operating temperature range: -40 to 125°C
Thermal resistance ?JA (°C/W): 23
Noise (uVrms): 150
PSRR @ 100 KHz (dB): 32
Accuracy (%): 2.5
Dropout voltage (Vdo) (Typ) (mV): 310
Iq (Typ) (mA): 0.11
Package size:
- 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
Images are for illustration only; actual product may vary.