Description

The Bay Linear LM3940 is a high accuracy, low dropout voltage regulator. It has a low dropout voltage of only 40mV at light loads and 350mV (Typ.)@ 1.0A, and a low quiescent current of 240µA typical. The LM3940 is designed for low voltage applications that require a lower dropout voltage and faster transient response. It is an excellent choice for powering low voltage applications and as a post regulator for switching supplies. The LM3940 offers full protection against over-current faults, reversed input polarity, reversed load insertion, and positive and negative transient voltage. On-Chip trimming adjusts the reference voltage to 1%. It is available in a 3-pin SOT-223, TO-220 & TO-263 package compatible with other 3 terminal regulators. The LM3940 is also offered in a new LPDD (Low Profile TO-263) package with a thickness ranging from 4.47 mm (DD) to 1.27 mm (LPDD).

Specifications and features

• High output accuracy of 1%
• Fix Output 5.0v & 3.3V
• Output Current of 1.25A
• Low Dropout Voltage
• Low quiescent current
• Extremely Tight Load & Line Regulation
• Reverse-battery and “Load Dump” Protection
• Zero Current Shutdown Mode (5-pin version)
• Offer in TO-263, TO-252, TO-220, SOT-223, & New Slim LPDD
• Similar to industry Standard LM3940

Application Scenarios

• Powering VGA & Sound Card
• LCD Monitor
• Battery Powered Equipments/Laptop & Notebook
• SMPS Post Regulator / DC to DC Modules
• High Efficiency Linear Power Supply
• Adjustable Power Supply
• Bar Code Scanners