LM7809 Pinout, Uses, Equivalent, Specs, Applications and Other Details

7809 is an IC of LM78xx series of fixed positive voltage regulators. In this post we are going to discuss LM7809 pinout, uses, equivalent, specs, applications and other details about where and how to use this IC.


LM7809 Pinout, Uses, Equivalent, Specs, Applications and Other Details



LM7809 IC Features / Technical Specifications:

  • TO-220 Package
  • The Output current is 1A to 1.5A
  • Built-in short circuit protection function
  • Buit-in over heat protection / shutdown function
  • Low cost
  • Reliable to use commercially
  • Provides stable and fixed output of 9V.
  • Maximum input voltage the IC can handle is 35V DC.
  • The sleep mode or standby current consumption is only 8mA


LM7809 Description:

LM7809 is a fixed positive voltage regulator IC. The IC provides fixed 9V ouput with 1A to 1.5A. To achieve a fixed and stable output voltage of 9V and 1.5 ampere the input voltage should be 11V and 2 ampere. If the input voltage will be lower than 11V then the IC will not provide fixed 9V because it requires 2V above from its actual output voltage to provide a stable output. The maximum input voltage limit is 35V DC. A suitable heatsink is must to use with the IC because all the voltage difference will convert into heat in the IC. Moreover the IC also contains many built in features like over heat shutdown and short circuit protection that makes it reliable to use in many commercial applications and also in educational electronics projects.




Voltage Step Down

Power Supplies

Motor Drivers

Battery Chargers

Solar Supplies

Microcontroller power supplies


Replacement and Equivalent / Other Part Numbers:

LM2940CT-9.0, LM340T9, LM340AT9.0 voltage regulators ICs can be replaced with LM7809, but if any reason you can’t get these substitute ICs then an LM317 adjustable regulator IC can also be used as a fixed 9V output regulator for doing so just adjust the variable resistor used with this IC set it at 9V or you can also use fixed resistor in the place of variable resistor but you should know what fixed resistor to use to get 9V from LM317. This information through LM317 output voltage calculator available online.


LM7809 9V DC Power Supply Circuit:

The figure below shows a circuit diagram of a LM7809 power supply circuit.

9V Power Supply Circuit using LM7809


How to Safely Long Run in a Circuit:

For reliable and long life performance in your circuits it is recommended to not provide more than 35V to the IC, do not drive load of more than 1.5A, use a suitable heatsink with the IC and always operate in temperature above 0 degree centigrade and below +125 centigrade. The storage temperature should be between -65 to +150 centigrade.



To Download the datasheet just copy and paste the below link in your browser.


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