LM7812 - 12V Voltage Regulator IC

The LM78XX series of voltage regulators are commonly used in various electronics appliances and projects. LM7812 IC comes in the family and provides a fixed regulated output of 12V DC for a variable input voltage range of 14.5 to 27V DC.

 

Features and Specifications

This section mentions some of the important features and specifications of the 7812 IC:

1. Input Voltage: 14.5V to 27V DC
2. Output Voltage: 11.75V - 12.25V DC
3. Output Current (Typical): 1A
4. Peak current: 2.2A
5. Dropout voltage: 2V

 

LM7812 Pinout Configuration 

The IC comes in compact packaging with 3 pins for input/output and ground pins. The table below can be referred to understand the pin configuration of the IC.

Pin Number	Pin Type	Pin Description
1	IN	Positive Input Voltage
2	GND	Ground
3	OUT	Positive Output Voltage

 

Typical Application Circuit of a 78XX Voltage Regulator

The circuit shown below is a typical application circuit of the 7812 IC. The circuit includes a power source, two capacitors, and the voltage regulator IC.

As we can observe through the voltage probe, when an input voltage of ~25V is provided through the 7812 IC, the output voltage we obtain is 12V DC. The image below represents all the internal circuit components of the regulator IC.

The application circuit shown above also consists of two ceramic capacitors. Ceramic capacitor C1(0.33uF) is used to deal with the problems of input impedance, whereas the capacitor C2(0.1uF) is used to provide a stable output voltage. Ceramic capacitors are used here because they are faster than the electrolytic capacitors.

 

Alternatives 

LM2596, LTC3780

 

Available Packages 

TO-220

 

Applications 

Here are some of the applications of the 7812 IC.

1. Remote control cars
2. Toys
3. Phone chargers
4. Power distribution circuits
5. Current Limiter for certain applications
6. Regulated Dual Supply

 

2D Model and Dimensions

Below is the 2D model of the voltage regulator IC along with its dimensions in inches(millimeters). The following information can be used to design the custom footprints and be used for PCB designing and CAD modelling.