LM7811

The LM7811 is a linear voltage regulator IC manufactured by National Semiconductor, now part of Texas Instruments. It belongs to the LM78xx series of three-terminal regulators, specifically designed to provide a fixed output voltage of 11 volts. This makes it suitable for applications requiring a stable and well-regulated 11V supply from a higher input voltage.

Like other LM78xx series regulators, the LM7811 features built-in thermal overload protection and short-circuit current limiting. These features protect the device and the connected circuitry from damage under fault conditions. The regulator requires an input voltage that is a few volts higher than the desired output voltage to maintain regulation; typically, a difference of 2-3 volts is sufficient.

The LM7811 is commonly available in a TO-220 package, which allows for easy mounting to a heatsink when dissipating significant power. This is important because linear regulators convert excess input voltage into heat. The device operates within a specified input voltage range and a defined operating temperature range. Its simplicity and reliability have made it a popular choice for a variety of consumer electronics, industrial control systems, and other applications where a steady 11V supply is needed. It is typically used in conjunction with input and output capacitors to ensure stable operation and filter out noise.