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1-A, low-dropout voltage regulator for 5-V to 3.3-V conversion

NEW - Custom reel may be available
Inventory: 41,448

Quality information

RoHS Yes
Lead finish / Ball material SN
MSL rating / Peak reflow Level-1-260C-UNLIM
Material content View
DPPM / MTBF / Fit rate View
Qualification summary View
Ongoing reliability monitoring View
Device marking View

Packaging information

Package | Pins Package qty | Carrier Operating temperature range (°C)
SOT-223 (DCY) | 4 2,000 | LARGE T&R
Custom reel may be available
-40 to 125
Package | Pins SOT-223 (DCY) | 4
Package qty | Carrier 2,000 | LARGE T&R
Custom reel may be available
Operating temperature range (°C) -40 to 125
View TI packaging information

Features for the LM3940

  • 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

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Description for the LM3940

The LM3940 is a 1-A low-dropout regulator designed to provide 3.3 V from a 5-Vsupply.

The LM3940 is ideally suited for systems which contain both 5-V and 3.3-V logic, withprime power provided from a 5-V bus.

Because the LM3940 is a true low dropout regulator, it can hold its 3.3-V output inregulation 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 loadcurrent can be delivered without using an additional heatsink.

The surface mount DDPAK/TO-263 package uses minimum board space, and gives excellentpower dissipation capability when soldered to a copper plane on the PC board.


Qty Price (USD)
1-99 1.195
100-249 0.92
250-999 0.677
1,000+ 0.484

Additional package qty | carrier options

Package qty | Carrier 1,000 | LARGE T&R
Inventory 194,577
Qty | Price (USD) 1ku | 0.484 1-99 1.195 100-249 0.92 250-999 0.677 1,000+ 0.484
Custom reel may be available