LM78xx series ICs are available in the market from various manufacturers like LM7806, LM7805, LM7809, LM7812, LM7810, LM7824 and LM7815. This series of voltage regulators is available with three terminals in the TO-220 package. So, each voltage regulator has thermal shutdown, internal current limiting & safety operating area protection features which makes them durable. These ICs are mainly designed as fixed voltage regulators which can be utilized with exterior components to get adjustable voltages & currents. Thus, this article provides brief information on LM7808 IC, pinout, specifications, and its applications.
What is LM7808 IC?
LM7808 IC is a positive three-terminal voltage regulator, available in a TO-220 package that provides 8V DC fixed output even when the input voltage fluctuates. However, the input voltage should not be below the necessary voltage of the IC, which means 2V to 3V. So, this is a DC device, so the input voltage should be DC. In addition, the input current must be at least 2A to obtain 1.5A at the output.
The LM7808 IC is a linear voltage regulator. Thus, it is simple to utilize and doesn’t need any external components or circuitry for voltage regulation. This IC can be used for different applications which include local regulation, adjustable output voltages, eliminating distribution issues, eliminating noise, etc.
LM7808 IC Working
The LM7808 voltage regulator IC works by fixing the fluctuations of voltage within an input to protect the application circuit. This is an 8V IC that limits the output voltage to 8Volts for different input voltage ranges. So these regulator ICs use internal current limiting, safe-area compensation, and thermal shutdown which makes them indestructible essentially. If sufficient heat sinking is provided to this IC then they deliver above 1.0A o/p current and approximately 500 mA current without a heat sink.
LM7808 IC Pin Configuration:
The pin configuration of LM7808 IC is shown below. This IC includes 3-pins which are discussed below.
LM7808 IC Pin Configuration
- Pin-1 (Input): This is an input pin of the IC that allows the incoming DC voltage.
- Pin-2 (GND): This is the ground pin of the voltage regulator that sets the GND for the IC.
- Pin-3 (Output): This is an output pin of IC that supplies 8-volts regulated DC output.
Features & Specifications:
The features and specifications of LM7808 IC include the following.
- LM7808 IC is a voltage regulator IC.
- This IC includes three pins and is available in the TO-220 package.
- It has a Through Hole mounting style.
- It provides output current upto 1.5A.
- This IC has a Short circuit and overheat shutdown ability.
- These are reliable to utilize for commercial purposes.
- These are accurate & fixed 8V output.
- Its input voltage ranges from 10Volts to 35V DC
- This IC has a low standby current is 8mA only.
- It has one output.
- This IC has positive polarity.
- It has a fixed output.
- Minimum and maximum input voltage ranges from 10V to 35V.
- Its operating temperature ranges from 0 C to + 125 C.
- Its load and line regulation is 160mV.
Equivalent & Other Voltage Regulator ICs
Equivalent LM7808 ICs are; LM340-8.0 and LM2940-08 and other adjustable voltage regulators are; LM338, LM317, LM1084, etc.
How to Securely Long Run LM7808 IC within a Circuit?
To get long-term performance using LM7808 IC within a circuit, it is suggested not to drive > 1.5A load through it. So ensure to utilize a suitable heat sink through the regulator IC. Do not provide i/p voltage > 40V DC and operate this IC always in > 0 centigrade & < +125 centigrade temperature. Thus this IC must be stored between -65 degrees C to +150 degrees C at temperature.
230V 1A to 8V 1A Conversion Circuit with LM7808 IC
The 230V 1A to 8V 1A conversion circuit with LM7808 IC is shown below. So this circuit uses a 230V input AC supply and provides a positive 8V 1A DC output voltage.
The required components to make this power supply circuit mainly include; LM 7808 voltage regulator IC, 230V /12V, 1A step-down transformer, 1N7004 Diode bridge, 2200uF, 25V polar capacitor, 330nF, 100nV Non-polar capacitors, aluminum heat sink, veroboard or breadboard and connecting wires. So, connect this power supply circuit as per the simple circuit shown below.
230V 1A to 8V 1A Conversion Circuit with LM7808 IC
Working
The LM7808 IC is a significant component in this regulated power supply circuit. This is a monolithic IC, designed to provide a fixed 8V output voltage. So, this circuit working is very simple, whenever this regulator circuit gets 230V AC input voltage to the main winding of a T1 transformer then it steps down the voltage to 12V AC on its secondary winding.
After that, this step-down AC voltage rectifies and changes AC to DC voltage with a BR1 full bridge rectifier. So a C1 capacitor in the circuit is used for smoothing & filtering the DC voltage. After that, the 12V DC voltage can be regulated by the LM7808 voltage regulator IC to 8V constant DC and additional voltage can be changed into heat. Thus, the C2 and C3 capacitors in the circuit are used to reduce the ripple noise. So this power supply circuit provides 8V DC output.
Advantages & Disadvantages
The advantages of LM7808 IC include the following.
- The LM7808 IC has in-built current limiting, short circuit protection, and thermal shutdown features that make it resistant to overload.
- This IC has a secure operating region protection feature.
- This is a simple voltage regulator IC that doesn’t need any exterior components (or) circuitry for the regulation of voltage.
- This IC can be utilized with external components to make adjustable voltages & currents.
- This voltage regulator is available in different fixed output voltages.
- When sufficient heat sinking is provided to this IC then it delivers over 1A output current.
- These regulators maintain the power source voltage in tolerable limits. So they control fluctuating power supply or voltages that could be harmful to electrical machinery.
The disadvantages of LM7808 IC include the following.
- The input voltage should be higher as compared to the output voltage by the smallest amount, typically 2.5 V.
- The variation between the I/O voltages can be dissipated as heat. If the difference is greater then more heat can be produced. If the voltage regulator doesn’t include a heat sink, then can get smashed or malfunction.
- The LM7808 IC is less efficient as compared to other power supplies because a huge input power portion is wasted like heat.
- This IC is used for step-down operations only.
Applications
The applications of LM7808 IC include the following.
- The LM7808 is a fixed-voltage regulator IC that delivers an output current of up to 1.5 Amps.
- This IC can be utilized with exterior components to make adjustable o/p voltages & currents.
- It can be utilized as a power-pass element within precision regulation.
- This chip can be utilized for on-card regulation to remove noise & distribution issues.
- This regulator chip has a thermal shutdown feature that makes it resistant to overload.
- This IC has secure operating area protection.
- LM7808 IC is used within 8V power supplies, motor driver applications, battery charger circuits, solar power supply circuits, microcontroller applications, voltage step-down circuits, etc.
- These voltage regulator ICs are used in embedded systems, power supply design, consumer electronics, battery-powered devices, and communication equipment.
Please refer to this link for the LM7808 IC Datasheet.
Thus, this is an overview of LM7808 IC, pinout, features, specifications, circuit, working, pros, cons, and applications. The 7808 fixed voltage regulator IC is a reliable and robust 8Volts voltage regulator that plays a significant role in different electronic applications. This IC is capable of providing a stable 8V output from a wide input voltage range. So this IC has an in-built protection feature which makes them an excellent choice mainly for battery-powered circuits, power supply systems, electronic prototyping, and many more. The 7808 IC ensures that your electronic devices and projects operate efficiently and smoothly with its reliable performance. Here is a question for you, what is LM7805 IC?