L7805CV-DG

The L7805CV-DG from STMicroelectronics is a member of the L78 series of three-terminal positive voltage regulators, providing a fixed 5V output at up to 1.5A. Housed in a TO-220 through-hole package, this regulator integrates internal current limiting, thermal shutdown, and safe operating area protection. The -DG suffix indicates dry-pack packaging for moisture-sensitive storage. It is widely used as a local on-card regulator, eliminating distribution problems associated with single-point regulation in power supply designs.

The L7805CV-DG uses a series-pass transistor topology controlled by a feedback loop. A bandgap voltage reference provides a stable internal reference voltage. The output voltage is divided by an internal resistor network and compared against the reference by an error amplifier, which drives the series-pass transistor to maintain 5V at the output. If the output current exceeds the safe limit, the current limiting circuit reduces the drive to the pass transistor. If the junction temperature exceeds approximately 150°C, the thermal shutdown circuit turns off the pass transistor. The dropout voltage of approximately 2V means the input must be at least 7V to maintain 5V regulation.

• 5V logic power supply for microcontroller and digital circuits
• Local on-card regulation in distributed power systems
• Battery-powered device regulation with appropriate input voltage
• Industrial control system power rails
• Consumer electronics power supply stages