LM317 SOIC8 SMD Adjustable Voltage Regulator

Previously we have discussed some fixed voltage regulator ICs like LM7805, LM7806, LM7809, LM7812 and LM7815. All these ICs are designed to provide a fixed output voltage. But if there is requirement of adjustable output voltage then LM317 might be a good choice. LM317 is a widely used adjustable positive voltage regulator IC available in many different packages. The IC is widely used in commercial equipment and also by electronic students and learners. It is also one of a famous IC among electronic hobbyists and tinkerers. The main reason for its wide usage is because it contains entire adjustable regulated power supply circuitry in a single chip due to which one can easily make a low cost and reliable adjustable power supply of 1.2V to 37V DC output voltage with upto 1.5A output current capability and very low external components. Moreover the IC also contains many other features like short circuit protection, safe area and over heat protection which also makes it full proof and long term performer. Two external resistors can be used to adjust the output voltage of the IC. For getting a stable output the input voltage must be 2 to 3 volt higher than the output.

LM317 IC Features / 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