An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications, intellectual property matters . LM, LM Datasheet. DS – Rev 20 – May For further information contact your local STMicroelectronics sales office. The LM, LM are monolithic integrated circuits in TO, TOFP and DĀ²PAK packages intended for use as positive adjustable voltage regulators.

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This creates adjustable voltages. Adjustable 3-terminal positive voltage regulator Output voltage can be set to range from 1. The Resistor R1 1K and the potentiometer 10k together creates a potential difference at adjust pin which regulates the datasheett pin accordingly. Support Center Complete list and gateway to support services and resource pools.

The input pin receives the incoming, unregulated voltage. Support Center Video Center. The voltage which enters this lm3117 must be larger than the voltage it is feeding out.

LM Schematic Diagram Now that you know the pins, how do we modify the voltage to that which we want output?

We’re going to put 12 volts into the voltage regulator and regulate it down to 5V. As said earlier the IC has 3 pins, in which the input voltage is supplied to pin3 VIN then using a pair of datasbeet potential divider we set a voltage at pin 1 Adjust which will decide the output voltage of the IC that is given out at pin 2 VOUT. In this circuit, we want a regulated 5VDC as output. Product is in volume production Evaluation: No commitment taken to produce Proposal: Getting started with eDesignSuite.

How the adjustment pin is connected determines the output voltage as follows. LM Datasheet The datasheet for a LM goes much more depth than this article, which was only created to serve as a beginner’s guide to this voltage regulator. In packages with a heat-dissipating mounting tab, such as TOthe tab is connected internally to the output pin which may adtasheet it necessary to electrically isolate the tab or the heat sink from other parts of the application circuit.


Small footprint LDOs offer Meeting portable applications’ datasjeet. However, the 78xx device’s quiescent current is substantially higher and less stable. Now to make it act as a variable voltage regulator we have to set variable voltages at pin 1 which can be lm171 by using a potentiometer in the potential divider.

For example, the input voltage pin can be fed 12V, which the datashdet will regulate down to 10V.

LM3171 Datasheet

Failure to do this may cause the circuit to short. No availability reported, please contact our Sales office. Distributor Name Region Stock Min. They do not and cannot create voltage on their own. In use an LM commonly requires a heat sink to prevent the operating temperature rising too high. The same formulae can also km3171 used to calculate the value of resistor for you required output voltage.

From Wikipedia, the free encyclopedia. Please contact our sales support for information on specific devices. General terms and dtasheet.

Looking from the front of the voltage regulator, the first pin on the left is the Adjustable Pin, the middle is Vout, and the last pin on the right is V IN.

Views Read Edit View history. Product is datashfet volume production only to support customers ongoing production. To adjust output, we swap out resistor R2 value lj3171 a different resistance. Communications Equipment, Computers and Peripherals. One notable drawback of this IC is that it has a voltage drop of about 2. Generally, with regulators, unless they are low drop out regulators, you want the input voltage to be about 2 volts higher. Retrieved 31 March One easy way to do this is to use this online calculator to randomly substitute the value of resistors you have and check which output voltage you will get.


LM Datasheet, LM PDF Schematic, Manual, Equivalent – Fairchild Semiconductor

The LM is designed to compensate for these fluctuations internally, making such measures unnecessary. When it comes to variable voltage regulation requirements LM would most likely be the first choice.

Here you see we connect two resistors to the voltage regulator. Complete Technical Details can be found at the LM datasheet given at the end of this page.

Product is in volume production 0. The last pin of the LM is the output pin.

In our circuit, a motor is connected as a load which consumes around mA you can connect any load up to 1. The LM negative complement to the LM regulates voltages below, rather than above, the reference. Archived from the original on 17 December Key Features Output voltage range: Archived from the original PDF on 18 April ST Code dxtasheet Conduct Blog.

The LM relates in the same way to the fixed 79xx regulators. In other projects Wikimedia Commons. Higher regulated voltages are obtained by connecting the adjustment pin to a resistive voltage divider between the output and ground.

Product is under characterization. Media Subscription Media Contacts. In our setup now, these are the values we’re going to use.