LM3940 1A Low Dropout Regulator for 5V to 3.3V Conversion | TI.com

LM3940
This product has been released to the market and is available for purchase. For some products, newer alternatives may be available.
1A Low Dropout Regulator for 5V to 3.3V Conversion

 

Description

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 heatsink.

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

All trademarks are the property of their respective owners.

Parametrics

Compare all products in Linear regulators (LDO) Email Download to Excel
Part number Order Output options Iout (Max) (A) Vin (Max) (V) Vin (Min) (V) Vout (Max) (V) Vout (Min) (V) Fixed output options (V) Package Group Features Regulated outputs (#) Operating temperature range (C) Thermal resistance θJA (°C/W) Noise (uVrms) Approx. price (US$) Rating PSRR @ 100 KHz (dB) Accuracy (%) Dropout voltage (Vdo) (Typ) (mV) Iq (Typ) (mA) Package size: mm2:W x L (PKG)
LM3940 Order now Fixed Output     1     5.5     4.5     3.3     3.3     3.3     DDPAK/TO-263 | 3
SOT-223 | 4
TO-220 | 3    
    1     -40 to 125     23     150     0.55 | 1ku     Catalog     32     2.5     310     0.11     3DDPAK/TO-263: 155 mm2: 15.24 x 10.16 (DDPAK/TO-263 | 3)
4SOT-223: 46 mm2: 7 x 6.5 (SOT-223 | 4)
3TO-220: 47 mm2: 4.58 x 10.16 (TO-220 | 3)    
LP3872 Order now Fixed Output     1.5     7     2.5     5     1.8     1.8
2.5
3.3
5    
DDPAK/TO-263 | 5
SOT-223 | 5    
Enable
Power Good    
1     -40 to 125     40     100     1.41 | 1ku     Catalog       2     380     6     5DDPAK/TO-263: 155 mm2: 15.24 x 10.16 (DDPAK/TO-263 | 5)
5SOT-223: 45 mm2: 6.96 x 6.5 (SOT-223 | 5)