LM317 Constant Current Source Power Supply Circuit
LM317 Constant Current Source Power Supply
LM317 Constant Current Power Supply Circuit Diagram
LM317 Constant Current Power Supply Circuit Overview
![]() |
LM317 constant current source power supply circuit electrobuff.blogspot.com |
![]() |
LM317 constant current source power supply circuit electrobuff.blogspot.com |
![]() |
LM317 constant current source power supply circuit electrobuff.blogspot.com |
Watch my YouTube Video Tutorial
LM317 Linear Regulator IC Overview
The LM317 is a versatile voltage regulator integrated circuit (IC) that has been widely used in electronic circuits since its introduction by National Semiconductor (now part of Texas Instruments) in the 1970s. It is a three-terminal adjustable positive voltage regulator, meaning it can be configured to provide a regulated output voltage within a specified range.
![]() |
LM317 linear voltage regulator IC Pinout electrobuff.blogspot.com |
![]() |
LM317 linear voltage regulator IC Pinout electrobuff.blogspot.com |
Key Features of LM317:
Adjustable Output Voltage: One of the primary features of the LM317 is its ability to provide a variable and adjustable output voltage. By using external resistors, the user can set the desired output voltage within a specified range.
Wide Input Voltage Range: The LM317 can operate with a wide input voltage range, making it suitable for various applications. It can handle input voltages significantly higher than the desired output voltage.
Low Dropout Voltage: The dropout voltage is the minimum voltage required between the input and output for the regulator to maintain regulation. The LM317 has a low dropout voltage, enabling it to regulate the output even when the input voltage is close to the desired output voltage.
High Ripple Rejection: The IC exhibits high ripple rejection, which means it can effectively filter out AC voltage variations in the input, providing a stable DC output.
Current Limiting: The LM317 has built-in current limiting to protect the device from excessive currents. This feature enhances the reliability of the IC in various applications.
Thermal Shutdown: To prevent overheating, the LM317 includes a thermal shutdown mechanism. If the temperature exceeds a certain threshold, the IC will shut down temporarily until it cools down.
TO-220 Package: The LM317 is commonly available in a TO-220 package, making it easy to handle and dissipate heat. This package is widely used in electronic circuits and allows for easy mounting on heat sinks.
Common Applications:
Voltage Regulator: The primary application of the LM317 is as a voltage regulator to provide a stable and adjustable output voltage for powering electronic devices.
Power Supplies: The LM317 is frequently employed in the design of linear power supplies for various electronic systems, including hobbyist projects and commercial applications.
Battery Chargers: It is used in battery charging circuits to regulate the charging voltage for lead-acid batteries, Ni-Cd batteries, and other types.
Audio Amplifiers: The LM317 can be utilized in audio amplifier circuits to provide a stable supply voltage for amplifier components.
Instrumentation and Control Systems: Due to its versatility, the LM317 finds applications in instrumentation and control systems where a stable and adjustable voltage is required.
The LM317's enduring popularity stems from its reliability, ease of use, and adaptability to a wide range of voltage regulation tasks in diverse electronic applications.
Leave a Comment