LM1084IT-3.3

Overview

The LM1084IT-3.3/NOPB is a fixed positive low-dropout linear regulator manufactured by Texas Instruments, originally part of the National Semiconductor portfolio. It provides a fixed 3.3 V output with a maximum continuous current capability of 5 A. The device operates within an input voltage range of 2.6 V to 27 V and features a typical dropout voltage of 1.3 V at full load. It is housed in a TO-220-3 through-hole package and supports an industrial operating temperature range from -40°C to +125°C.

Feature Summary

• Fixed 3.3 V output voltage eliminates external resistor requirements for standard applications
• Integrated thermal shutdown and current limiting protect against overload conditions
• Low dropout characteristic enables efficient regulation with minimal input-output differential

Applications

• Post-regulation stage for switching DC/DC converters
• Battery charger circuits requiring stable voltage rails
• General-purpose power supplies for embedded systems

Procurement Notes

Verify that the ordering suffix /NOPB indicates lead-free compliance and RoHS adherence as per manufacturer specifications. Confirm the package type matches the required TO-220-3 through-hole footprint. Ensure the fixed 3.3 V variant is selected rather than the adjustable version. Cross-reference the manufacturer designation between National Semiconductor legacy parts and current Texas Instruments documentation to ensure functional equivalence.

Selection Notes

Select this component when a fixed 3.3 V rail is required with up to 5 A load capacity. The TO-220-3 package is suitable for applications where through-hole mounting and adequate heat dissipation are prioritized over surface area constraints. Consider the 1.3 V typical dropout when designing the input voltage headroom. Verify that the thermal management strategy accommodates the power dissipation inherent in linear regulation at high currents.

Part Context

This device belongs to the LM1084 series of 5 A low-dropout positive regulators. The series includes fixed voltage options such as 3.3 V and 5.0 V, alongside an adjustable variant. The LM1084 family is designed to replace older standards like the LM317 while offering higher current capabilities and lower dropout voltages. It serves as a robust solution for medium-power linear regulation tasks in industrial and commercial environments.

Replacement Considerations

Publicly confirmed substitute part numbers are not available in the provided source material.