Product Summary

The LM3940 is a 1A low dropout regulator designed to provide 3.3V from a 5V supply. The device is ideally suited for systems which contain both 5V and 3.3V logic, with prime power provided from a 5V bus. Because the LM3940 is a true low dropout regulator, it can hold its 3.3V output in regulation with input voltages as low as 4.5V. The T0-220 package of it means that in most applications the full 1A of load current can be delivered without using an additional heatsink. The applications of the LM3940 include: Laptop/Desktop Computers, Logic Systems.

Parametrics

LM3940 absolute maximum ratings: (1)Storage Temperature Range: -65℃ to +150℃; (2)Operating Junction Temperature Range TO-220, TO-263, and SOT-223: -40℃ to +125℃; (3)Lead Temperature (Soldering, 5 seconds): 260℃; (4)Input Supply Voltage: 7.5V; (5)ESD Rating: 2 kV.

Features

LM3940 features: (1)Output voltage specified over temperature; (2)Excellent load regulation; (3)Guaranteed 1A output current; (4)Requires only one external component; (5)Built-in protection against excess temperature; (6)Short circuit protected.

Diagrams

LM3940 typical application

Image Part No Mfg Description Data Sheet Download Pricing
(USD)		 Quantity
LM3940
LM3940
Other

Data Sheet
Negotiable 
LM3940IMP-3.3/NOPB
LM3940IMP-3.3/NOPB
National Semiconductor (TI)
Low Dropout (LDO) Regulators 1A LDO REG
Data Sheet
0-1: $1.00
1-25: $0.79
25-100: $0.71
100-250: $0.61
LM3940IMPX-3.3
LM3940IMPX-3.3
National Semiconductor (TI)
Low Dropout (LDO) Regulators
Data Sheet
0-2000: $0.38
2000-4000: $0.35
4000-6000: $0.34
6000-10000: $0.33
LM3940IMPX-3.3/NOPB
LM3940IMPX-3.3/NOPB
National Semiconductor (TI)
Low Dropout (LDO) Regulators
Data Sheet
0-1: $0.92
1-25: $0.71
25-100: $0.64
100-250: $0.53
LM3940IS-3.3
LM3940IS-3.3
National Semiconductor (TI)
Low Dropout (LDO) Regulators
Data Sheet
0-45: $0.93
45-135: $0.85
135-270: $0.76
270-540: $0.65
LM3940IS-3.3/NOPB
LM3940IS-3.3/NOPB
National Semiconductor (TI)
Low Dropout (LDO) Regulators 1A LDO REG
Data Sheet
0-1: $1.07
1-25: $0.86
25-100: $0.78
100-250: $0.69
LM3940ISX-3.3
LM3940ISX-3.3
National Semiconductor (TI)
Low Dropout (LDO) Regulators
Data Sheet
0-500: $0.50
500-1000: $0.50
1000-2500: $0.47
2500-5000: $0.45
LM3940IT-3.3
LM3940IT-3.3
National Semiconductor (TI)
Low Dropout (LDO) Regulators
Data Sheet
0-45: $0.91
45-135: $0.82
135-270: $0.74
270-540: $0.59