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.

Author: Kigazahn Aramuro
Country: Jordan
Language: English (Spanish)
Genre: Health and Food
Published (Last): 11 April 2017
Pages: 107
PDF File Size: 5.86 Mb
ePub File Size: 7.8 Mb
ISBN: 748-4-34102-156-9
Downloads: 95952
Price: Free* [*Free Regsitration Required]
Uploader: Tujind

These resistors determine the voltage that the voltage regulator adjusts to and outputs. Key Features Output voltage range: Remember, voltage regulators are just devices that regulate voltage down to a certain level.

LM Voltage Regulator

It can supply more than 1. It xatasheet many application circuits in its datasheet, but this IC is known for being used as a variable voltage regulator. Distributor Name Region Stock Min. You can adjust it to any voltage within the range that the voltage regulator supports. In our setup now, these are the values we’re going to use.

They do not and cannot create voltage on their own. As said earlier the IC has 3 pins, in which the input voltage is supplied to pin3 VIN then using a pair of resistors potential divider om3171 set a voltage at pin 1 Adjust which will decide the output voltage of the IC that is given out at pin 2 VOUT.

Because of this, the error term in the formula cannot be ignored and the value of the low-side resistor becomes more critical.

This is the advantage of adjustable voltage regulators. Product is in volume production Evaluation: Here you see we connect two resistors to the voltage regulator.


Media Subscription Media Contacts.

LM – V to 37 V adjustable voltage regulators – STMicroelectronics

Getting started with eDesignSuite. How the adjustment pin is connected determines the output voltage as follows. Support Center Complete list and gateway to support services and resource pools.

The alternative is to use a switching voltage regulator which is usually more efficient but has a larger footprint and requires a larger number of associated components.

LM3171 Datasheet

When it comes to variable voltage regulation requirements LM would most likely be the first choice. Now the voltage output should be near 10V. Linear regulators inherently waste power, the power dissipated is the current passed multiplied by the voltage difference between datashset and output. Now swap out the R2 resistor and place a 1.

Like the LM, each of the 78xx regulators is designed to adjust the output voltage until it is some fixed voltage catasheet the adjustment pin which in this case is labelled ” ground “. The LM negative complement to the LM regulates voltages below, rather than above, the reference. Selectors Simulators and Models. Product is in volume production. Higher regulated voltages are obtained by dataxheet the adjustment pin to a resistive voltage divider between the output and ground.

However, the 78xx device’s quiescent current is substantially higher and less stable. This is the trade-off for using linear regulators which are a simple way to provide a stable voltage with few additional components.

Adjustable – The Adjustable pin Adj is the pin which allows for adjustable voltage output. This can help you find the exact resistor value needed for a circuit. How to use LM Accidenti come scotta questo transistor.

The input pin receives the incoming, unregulated voltage. Please contact our sales support for information on specific devices. One notable drawback of this IC is that it has a voltage drop of about 2. C2 is needed if the device is far from any filter capacitors.


LM is a 3-terminal regulator IC and it is very simple to use. Product is in design stage Target: Since we want 5 volts to be output, we must calculate which value of R2 will yield an output of 5 volts. The LM Voltage Regulator is a 3-terminal adjustable voltage regulator which can supply an output voltage adjustable from 1.

LM Schematic Diagram Now that you know the pins, how do we modify the voltage to that which we want output? In use an LM commonly requires a heat sink to prevent the operating temperature rising too high. This page was last edited on 6 Julyat To feed a circuit the regulated 5 volts, we just dataheet it to the output pin.

The voltage which enters this pin must be larger than the voltage it is feeding out. If you need to calculate output voltages or which resistor R2 value you would need for a circuit, see our LM Resistor and Voltage Calculator. If the adjustment pin is connected to lm3117 the output pin delivers a regulated voltage of 1.

l3171 You can vary the output voltage by simply varying the potentiometer. To find out more details about it, see the datasheet which is attached below: General terms and conditions. Views Read Edit View history. Now that we’ve dealt with the input pin, we must now deal with the adjustable pin Adj.

Menu Products Explore our product portfolio. By using this site, you agree to the Terms of Use and Privacy Policy.

Computers and Peripherals Data Center.