LD1117-1.8

Overview

The UMW LD1117-1.8 is a positive low dropout linear voltage regulator providing a fixed 1.8V output with up to 1A current capability. It features a typical dropout voltage of 1.2V at full load and maintains an output accuracy within 1.5%. The device includes internal thermal shutdown and current limiting protections, operates across a junction temperature range of -40°C to 125°C, and supports input voltages up to 12V.

Feature Summary

• Fixed 1.8V output with 1.5% tolerance
• Integrated thermal shutdown protection
• Internal current limiting circuitry
• Low dropout performance at high currents

Applications

• Laptop, Palmtop, and Notebook Computers
• Battery Charger Systems
• Cellular Phone Power Supplies
• Cordless Telephones
• Portable Instrumentation

Procurement Notes

Verify the specific package variant (SOT-223-3L, TO-252-2L, or SOT-89-3L) required for your design, as the datasheet lists multiple options. Confirm that the 1.5% output voltage tolerance meets your system requirements. Ensure adequate thermal management is implemented, as power dissipation is internally limited based on ambient temperature and thermal resistance.

Selection Notes

Select this component when a stable 1.8V rail is needed for portable electronics. It is suitable for post-regulation in switching power supplies due to its ripple rejection capabilities. Consider the available packages for space constraints; surface mount options like SOT-223-3L offer thermal optimization. Verify input voltage ranges do not exceed the 12V maximum rating under all operating conditions.

Part Context

The LD1117 series from UMW is designed as a cost-effective solution for general-purpose power management. It utilizes an NPN pass transistor driven by a PNP to ensure high efficiency. The family includes both adjustable and fixed voltage versions, offering flexibility for various digital logic and analog circuit supply needs in consumer and industrial applications.

Replacement Considerations

Check pinout compatibility if substituting with other LDOs. Verify that replacement devices support the same 1A current rating and 1.8V fixed output. Ensure thermal characteristics and protection features are equivalent to maintain system reliability.