# LM317 Data Sheet PDF – 1.5A, Adjustable Voltage Regulator

Part Number: LM317

Function: 3-terminal 1.5A positive adjustable voltage from 1.3V to 37V regulator.

Package: TO-220, TO-220FP, D2Pak type

Manufacturer: STMicroelectronics

Image and Pinouts:

## Description

The LM217, LM317 are monolithic integrated circuits in TO-220, TO-220FP and D²PAK packages intended for use as positive adjustable voltage regulators. They are designed to supply more than 1.5 A of load current with an output voltage adjustable over a 1.2 to 37 V range. The nominal output voltage is selected by means of a resistive divider, making the device exceptionally easy to use and eliminating the stocking of many fixed regulators.

## Features

1. Output voltage range: 1.2 to 37 V

2. Output current in excess of 1.5 A

3. 0.1% line and load regulation

4. Floating operation for high voltages

5. Complete series of protections: current limiting, thermal shutdown and SOA
control

## Frequently Asked Questions Regarding the LM317

Q: What is the maximum input voltage for the LM317?
A: The maximum input voltage for the LM317 is 40 volts. However, this may be lower depending on the specific version of the LM317 being used and the surrounding circuitry.

Q: What is the maximum output current for the LM317?
A: The maximum output current for the LM317 is typically 1.5 amps, but this may be lower depending on the specific version of the LM317 being used and the surrounding circuitry.

Q: How do I calculate the output voltage for the LM317?
A: The output voltage of the LM317 can be calculated using the formula VOUT = 1.25V x (1 + R2/R1), where R1 and R2 are the values of the resistors connected to the ADJ pin and ground, respectively.

Q: How do I select the values of the resistors for the LM317?
A: The values of the resistors R1 and R2 can be selected based on the desired output voltage using the formula mentioned in the previous answer. It is important to note that the values of the resistors should be chosen such that the current through the resistors is within the range of 1 to 10 mA.

Q: Can the LM317 be used as a current regulator?
A: Yes, the LM317 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.