LD1117S33TR

Overview

The LD1117S33TR is a fixed-output low-dropout linear voltage regulator manufactured by STMicroelectronics. It provides a fixed positive output voltage of 3.3 V with a maximum continuous output current of 800 mA. The device operates within an input voltage range of 3.3 V to 15 V and features a typical dropout voltage of 1 V at full load, with a maximum specified dropout of 1.2 V at 800 mA. It utilizes a SOT-223 surface-mount package (TO-261AA) and includes internal thermal overload and short-circuit protection circuits.

Feature Summary

• Fixed 3.3 V output voltage with ±1% tolerance at 25 °C
• Integrated thermal overload and short-circuit protection
• High efficiency via NPN pass transistor design

Applications

• Battery-powered systems requiring efficient step-down regulation
• Post-regulation for switching power supplies
• General-purpose 3.3 V logic supply generation

Procurement Notes

Verify the specific suffix 'TR' indicates tape-and-reel packaging when sourcing. Confirm the manufacturer is STMicroelectronics to distinguish from other LDO families. Ensure the application circuit includes the required minimum output capacitance for stability as defined in the official datasheet.

Selection Notes

Select this component for applications requiring a fixed 3.3 V rail with up to 800 mA load capability. The SOT-223 package offers thermal optimization through its exposed pad. Consider the 15 V maximum input rating and ensure the input-to-output differential does not exceed safe operating limits under all conditions.

Part Context

This part belongs to the LD1117 series of adjustable and fixed low-dropout positive voltage regulators. The series supports output currents up to 800 mA and is available in multiple packages including SOT-223, DPAK, SO-8, and TO-220. The S33 variant specifically denotes the fixed 3.3 V output option within this family.

Replacement Considerations

NCV1117ST33T3G is a documented alternative from ON Semiconductor offering similar functionality.