Introduction about IC LM7805 :
In this page, we will discuss one of the most commonly used regulators IC's, the 7805 voltage regulator IC. AS we know that a regulated power supply is very much essential for several electronic devices due to the semiconductor materials employed them have a fixed rate of current as well as voltage.
One of the most important sources of dc supply is batteries, but while using batteries, it is very sensitive electronics circuit is not a good idea as batteries eventually drain out ad lose their potential over time.
7805 is a three-terminal linear voltage regulator IC with a fixed output voltage of 5V which is useful in a wide range of applications. Currently, the 7805, voltage regulator IC is a manufactured by many companies like texas instrument, ON semiconductor, ST microelectronics, diodes incorporated, Infineon technologies, etc
LM7805 pinout diagram :
LM7805 is shown in the figure has a three-terminal device with the three pins being Input, Ground, and Output.
Input: Pin 1 is the input pin. A positive unregulated voltage is given as the input to this pin.
Ground: Pin 2 is the ground pin. It is common to both input and output.
Output: Pin 3 is the output pin. The output regulated 5V is taken at this pin of the IC.
7805 Regulator Features :
- 5V positive voltage regulator.
- Operating current is 5MA.
- Minimum input voltage is 7V.
- Maximum input voltage is 25V.
- 5Ω load resistor.
- Required very minimum external component to fully function.
- Available in TO-220 and KTE package.
- It can deliver up to 1.5A of current.
- Internal thermal overload and short circuit current limiting protection is available.
- Junction temperature maximum of 125-degree celsius.
- This IC has both internal current limiting and thermal shutdown features.
Application of LM7805 :
- It can be used regulated dual supply.
- The constant +5V output regulator microcontrollers and sensors in most of the projects.
- It is used in a wide range of circuits.
- It is used as a fixed output regulator.
- It can be used current limiter for certain applications.
- This IC can be used regulated DC voltage regulator.
- The output polarity reversal protection circuit.
- Reverse bias protection circuit.
- Used as a positive regulator in negative configurations.
- Used in the current regulator.
- LM7805 IC can be used as an adjustable output regulator.
Conclusion :
- The most important point is that the input voltage should always be greater than the output voltage.
- The input current and the output current are almost identical means that when a 7.5V, 1A supply is given at input the output will be 5V, 1A.
- The remaining power is dissipated as heat and hence a heat sink like the one shown below must be used with LM7805 IC.