LM317T LM317 Voltage Regulator IC LM317 IC Adjustable Voltage Regulator 1.2V to 37V 1.5A TO-220 3 Pin Leads LM317 Transistor IC

Description: LM317T  Voltage Regulator IC 

LM317T LM317 Voltage Regulator IC LM317 IC Adjustable Voltage Regulator 1.2V to 37V 1.5A TO-220 3 Pin Leads LM317 Transistor IC

LM317 variable voltage regulators. STMicroelectronics manufacturer’s part number LM317T. The output voltage is adjustable between positive 1.2 to 37 V. The output current varies between 2.2A for Vin-Vout ≤ 15V and 400mA at Vin-Vout = 40V.

The LM317 adjustable positive voltage regulator is capable of supplying in excess of 1.5A over a 1.2V to 37V output range. They are exceptionally easy to use and require only two external resistors to set the output voltage. Further, both line and load regulation are better than standard fixed regulators.

Beside replacing fixed regulators, the LM317 is useful in a wide variety of other applications. Since the regulator is “floating” and sees only the input to output voltage differential, supplied of several hundred volts can be regulated as long at the maximum input to output voltage differential (of 40V) is not exceeded (i.e. avoid short-circuiting the output).

The LM317 offers full overload protection. Included on the chip are current limit and thermal overload protection.

The LM317T is a popular variable voltage regulator that is used in power regulation circuits by hobbyists and professionals alike. The output voltage of LM317 can be adjusted from 1.2V to 37V with a maximum output current rating of 1.5A. The IC is commonly used for voltage regulation and current regulation circuits in chargers and other power modules. It comes in a breadboard friendly TO220 package and required very simple external components, few resistors, and a capacitor to operate as a function circuit. It can be used in positive voltage regulator circuits, Variable Power Circuits like battery chargers, and are commonly used in Desktop PC, DVDs, and other consumer products.

 Technical Specifications

• Capable of providing upto 1.5A current at the output.
• Voltage adjustable from 1.2V to 37V
• Requires low external components
• Requires only two external resistors for output adjustment.
• Capable of short circuit protection
• Over heat shutdown function
• Low price
• Reliable to use in commercial applications
• Maximum input voltage is 40V DC
• Low standby current

Features:

• Model: LM317
• Type: Voltage Regulator
• Output voltage range: 1.2 to 37 V.
• Output current in excess of 1.5 A.
• 0.1 % line and load regulation.
• Floating operation for high voltages.
• Complete series of protections: current limiting, thermal shutdown and SOA control.
• Package: TO-220

Application Circuit

The application circuit shown in the above “LM317 IC pinout” image can be used to make LM317 power supply. The maximum input voltage can be applied to the circuit is 40V DC with 2 to 3 ampere. The output is adjustable from 1.2V to 37V DC with max output current of 1.5A. The output voltage can be adjusted with the help of 5K variable resistor. The 40V input is not mandatory you can provide any voltage between 3V to 40V DC, depends on your output voltage requirements. For example if you want to build a 1.2V to 12V adjustable power supply then provide 3V higher than your maximum output voltage. In the above requirement of 1.2V to 12V supply the input voltage must not less than 15V.

Applications

• Voltage step down circuits
• Lab power supplies
• Battery Chargers
• Solar Power Supplies
• Microcontroller Related Applications
• DC to DC converters
• Portable Instruments

Replacement and Equivalent / Other Part Numbers

LM117, LM217, LM1086-ADJ, LT1086-ADJ, LT1117-ADJ, B29150, LM338, LM1084-ADJ. Some ICs may have different pin configuration from LM317, therefore check pin configuration before using in a circuit.

How to Safely Long Run in a Circuit

To get stable and long term performance from LM317 do not provide input voltage more than 40V DC, do not drive load of more than 1.5A, always use a proper heatsink with the IC and always operate in temperature above -55 centigrade and below +150 centigrade. The storage temperature is from -65 centigrade to +150 centigrade.