Texas Instruments LM3940
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. 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 heatsink.| Part No. | LM3940 |
|---|---|
| Datasheet | LM3940 Download |
| Manufacturer |  Texas Instruments |
| Description | 1-A Low-Dropout Regulator |
| Buy | Stock & Price |
FEATURES
●1 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 2
APPLICATIONS
● Laptop and Desktop Computers● Logic Systems 3
DESCRIPTION
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 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. Device Information(1) PART NUMBER PACKAGE BODY SIZE (NOM) SOT-223 (4) 6.50 mm x 3.50 mm LM3940 DDPAK/TO-263 (3) 10.18 mm x 8.41 mm TO-220 (3) 14.986 mm x 10.16 mm (1) For all available packages, see the orderable addendum at the end of the datasheet. Simplified Schematic *Required if regulator is located more than 1 inch from the power supply filter capacitor or if battery power is used. **See Application and Implementation.
