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 D²PAK packages intended for use as positive adjustable voltage regulators.
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Dagasheet that we’ve dealt with the input pin, we must now deal with the adjustable pin Adj. To adjust output, we swap out resistor R2 value for a different resistance.
Adjustable – The Adjustable pin Adj is the pin which allows for adjustable voltage output.
Computers and Peripherals Data Center. Failure to do darasheet may cause the circuit to short. 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.
The mechanism used is similar enough that a voltage divider can be used in the same way as with the LM and the output follows the same formula, using the regulator’s fixed voltage for V ref e.
So, if you are looking for a variable voltage regulator to deliver current up to 1. 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.
The device can be configured to regulate the current to a load, rather than the voltage, by replacing the low-side resistor of the divider with the load itself.
In use an LM commonly requires a heat sink to prevent the operating temperature rising too datadheet. No commitment taken to produce Proposal: Now the voltage output should be near 10V. Because of this, the error term in the formula cannot be ignored and the value of the low-side resistor becomes more critical.
The LM Voltage Regulator is a 3-terminal adjustable voltage regulator which can supply an output voltage adjustable from 1. How the adjustment pin is connected determines the output voltage as follows. 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 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.
The LM is an adjustable analogue to the popular 78xx fixed regulators. If you need to calculate output voltages or which resistor R2 catasheet you would need for a circuit, see our LM Resistor and Voltage Calculator.
This is the trade-off for using linear regulators which are a simple way to datawheet a stable voltage with few additional components. From Wikipedia, the free encyclopedia. This is where the regulated voltage in this case, 5 volts will come out.
In our setup now, these are the values we’re going to use. The capacitors C1 and C2 are used to clean up the power line. This is the dafasheet which allows us to adjust the voltage to the level we want. Wikimedia Commons has media related to LM and Voltage regulator circuits. If the adjustment pin is connected to ground the output pin delivers a regulated voltage of 1. Submitted by webmaster on 27 December Let’s see how the schematic is set up: Apart from using it as a variable voltage regulator, it can also be used as a fixed voltage regulator, current limiter, Battery charger, AC voltage regulator and even as an adjustable current regulator.
LM is a 3-terminal regulator IC and it is very simple to use. Linear regulators inherently waste power, the power dissipated is the current passed multiplied by the voltage difference between input and output.
C2 is needed if the device is far from any filter capacitors. This can help you find the exact resistor value needed for a datashee. Product is in design feasibility stage. Product is satasheet volume production 0. Marketing proposal for customer feedback. The voltage which enters this pin must be larger than the voltage it is feeding out.
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. We’re going to put 12 volts into the voltage regulator and regulate it down to 5V.
Not Recommended for New Design. LM Schematic Diagram Now that you know the pins, how do we modify the voltage to that which we want output? Higher regulated voltages are obtained by connecting the adjustment pin to a resistive voltage divider between the output and ground. Support Center Video Center.
You will discover it’s very close to 5 volts. Communications Equipment, Computers and Peripherals.
Small footprint LDOs offer Meeting portable applications’ needs. Generally, with regulators, unless they are low drop out regulators, you want the input voltage to be lm371 2 volts higher. This is the advantage of adjustable voltage regulators.
Below is the pinout: Product is in volume production Evaluation: In other projects Wikimedia Commons.