L7818CT

Overview

The L7818CT is a three-terminal positive linear voltage regulator from the STMicroelectronics L78 series, providing a fixed 18V output with a maximum continuous current of 1.5A. It operates within an input voltage range up to 35V and features a typical dropout voltage of 2V at 1A load. The device incorporates internal protection mechanisms including thermal overload shutdown, short-circuit current limiting, and safe operating area (SOA) protection. It is housed in a TO-220 package suitable for through-hole mounting and supports an extended operating temperature range.

Feature Summary

• Fixed 18V output voltage with high reliability
• Integrated thermal overload and short-circuit protection
• Capable of delivering over 1A output current with adequate heat sinking

Applications

• Local on-card regulation in electronic equipment
• Positive power supply units
• General-purpose linear regulation circuits

Procurement Notes

Verify component authenticity and datasheet alignment when sourcing. Confirm package type matches design requirements. Check for end-of-life status or obsolescence notices from the manufacturer. Ensure replacement parts maintain equivalent electrical specifications and pinout compatibility.

Selection Notes

Select this regulator for applications requiring a stable 18V DC source. Ensure input voltage remains within the 35V maximum limit. Verify thermal management capabilities are sufficient for the expected load current to prevent overheating. Consider alternative packages if surface-mount technology is required.

Part Context

This component belongs to the L78 series of three-terminal positive regulators. The series offers various fixed output voltages and is designed for wide-ranging industrial and commercial applications. It eliminates distribution problems associated with single-point regulation by allowing local placement near the load.