LM7812 3-Terminal 1A Positive Voltage Regulator

The LM78XX series including the LM7812 device are three terminal positive regulators available in the TO-220 package and with several fixed output voltages, making them useful in a wide range of applications. Each type employs internal current limiting, thermal shut down and safe operating area protection, making it essentially indestructible. If adequate heat sinking is provided, they can deliver over 1A output current. Although designed primarily as fixed voltage regulators, these devices can be used with external components to obtain adjustable voltages and currents.

Features:

Output Current up to 1A
Output Voltages of 5, 6, 8, 9, 10, 12, 15, 18, 24
Thermal Overload Protection
Short Circuit Protection
Output Transistor Safe Operating Area Protection

LM7812 Pin Assignment:

LM3940 1A Low Dropout Regulator

The LM3940 is a 1A low dropout regulator designed to provide 3.3V from a 5V supply. The LM3940 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 the LM3940 means that in most applications the full 1A of load current can be delivered without using an additional heatsink. The surface mount TO-263 package uses minimum board space, and gives excellent power dissipation capability when soldered to a copper plane on the PC board.

Typical application:

LM7805 5V Voltage Regulator

One of the most common and useful voltage regulators ever is the LM7805. It is a versatile linear regulator where in its TO-220 package can provide up to one amp of current at 5V. The only support circuitry needing to be a couple of capacitors to prevent high frequency oscillations on the outputs.

It is an absolute necessity for any TTL logic design and a great regulated voltage source for a wide assortment of projects.