LD1117D33CTR

Overview

The LD1117D33CTR is a fixed positive linear low-dropout voltage regulator manufactured by STMicroelectronics. It provides a fixed output voltage of 3.3V with a maximum continuous output current of 800mA. The device supports an input voltage range up to 15V and features a typical dropout voltage of 1.3V at full load. It incorporates internal thermal overload protection and current limiting to ensure safe operation under fault conditions. The component operates within a temperature range of -40°C to +125°C and utilizes an 8-SOIC surface-mount package.

Feature Summary

• Fixed 3.3V output configuration for stable power supply applications
• Integrated thermal overload and short-circuit current limiting protection
• Low quiescent current consumption optimized for efficiency
• High power supply rejection ratio for noise reduction

Applications

• Battery-powered systems requiring efficient voltage regulation
• Post-regulation stages for switching power supplies
• General-purpose power supply circuits in consumer electronics

Procurement Notes

Verify the specific suffix 'CTR' corresponds to the tape-and-reel packaging format required for automated assembly processes. Confirm that the 8-SOIC footprint matches the target PCB design constraints. Ensure compliance with RoHS3 directives if environmental regulations apply to the final product deployment. Cross-reference the manufacturer part number against official distributor catalogs to validate authenticity and current production status before procurement.

Selection Notes

Select this component when a fixed 3.3V rail is needed with moderate current demands up to 800mA. The SO-8 package offers a balance between thermal performance and board space efficiency compared to larger through-hole options. Consider the dropout voltage characteristics relative to the minimum input voltage available in the system design. Evaluate the thermal dissipation requirements based on the expected load current and ambient operating temperatures.

Part Context

This device belongs to the LD1117 family of low-dropout regulators, which are designed for high-efficiency power management using NPN pass transistors. The family includes adjustable versions and various fixed output voltages such as 1.2V, 1.8V, 2.5V, and 5.0V. The LD1117 series is widely used in applications where low cost, small form factor, and reliable regulation are prioritized over ultra-low noise specifications.

Replacement Considerations

LM1117MPX-33NOPB is documented as a similar alternative from onsemi.