LM317 Data Sheet – Adjustable Voltage Regulator – Unisonic

What is LM317?

The IC provides a constant output voltage, regardless of variations in the input voltage or load current, making it ideal for use in a variety of applications, including power supplies, battery chargers, and voltage regulators.


Package: TO-220, TO-263, TO-252, TO-3, SOT-223 Type

Manufacturer: Unisonic Technologies

Image and Pinouts:

LM317 datasheet



The UTC LM317 is an adjustable 3-terminal positive voltage regulator, designed to supply 1A of output current with voltage adjustable from 1.3V ~ 37V.

This is a three-terminal positive voltage regulator integrated circuit that is commonly used in electronic circuits to provide a variable output voltage.


1. Output voltage adjustable from 1.3V ~ 37V

2. Output current in excess of 1A

3. Internal short circuit protection.

4. Internal over temperature protection.

5. Output transistor safe area compensation


Frequently Asked Questions Regarding the LM317

Q1: Can this IC be used as a current regulator?
A1: Yes, It can be used as a current regulator by connecting a resistor in series with the load and adjusting the output voltage such that the desired current flows through the load. The current flowing through the load can be calculated using Ohm’s law: I = V/R.

Q2: What are some common applications of the LM317?
A2: It is commonly used in power supply circuits, battery charger circuits, and voltage regulator circuits. It is also used in audio amplifier circuits and as a current regulator in LED driver circuits.

Q3: Can this IC be used with a negative input voltage?
A3: No, It is designed to work with positive input voltages only. To use the LM317 with a negative input voltage, a negative voltage regulator such as the LM337 can be used instead.

Q4: How do I dissipate heat when using the device?
A4: it can generate significant amounts of heat when regulating high currents or when there is a large difference between the input and output voltages.

LM317 Datasheet PDF Download

LM317 pdf

Other data sheets are available within the file:

LM317AA3-R, LM317T30Y, LM317TA3-T, LM317TF3T

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