Linear Regulators

Linear regulator is a type of IC voltage regulator, in which the regulating element is a transistor that operates in its linear path of operation. The working of these linear regulators is also based on passive devices like zener diodes operated in their breakdown region. The regulating element acts as a variable resistor. The variable resistor provides a clear output without introducing any noise component. Linear regulators can exist in discrete as well as in integrated circuit form.

Working Principle
A linear regulator operates on the basis of an active device like vacuum tube, transistors, etc. The transistor or any other device is used as one half of a potential divider to monitor the output voltage. There exists a feedback circuit that compares the output voltage to a reference voltage to adjust the input to the transistor. This in turn helps to keep the output voltage constant.

All linear regulators require an input voltage, which is minimum or little higher than the desired output voltage. The minimum voltage is referred as the drop-out voltage.

Uses & Applications
Some of the areas where linear voltage regulators are used includes:

• Battery operated equipments
• Semiconductors
• Cell phones
• Camera modules
• Imaging sensors
• Portable media players