LD1117D33

Overview

The LD1117D33 is a fixed-output positive low-dropout linear voltage regulator manufactured by STMicroelectronics. It provides a stable 3.3 V output with a maximum continuous current of 950 mA. The device supports a maximum input voltage of 15 V and operates within an ambient temperature range of 0 °C to +125 °C. Key electrical parameters include a typical dropout voltage of 1 V, a line regulation of 6 mV, and a load regulation of 10 mV. Quiescent current is specified at 10 mA. The unit is housed in an SOIC-8 surface-mount package.

Feature Summary

• Fixed 3.3 V output configuration for standard logic power supply applications
• Integrated internal thermal overload and short-circuit protection mechanisms
• Low dropout voltage characteristic enabling efficient operation with minimal input-to-output differential

Applications

• Battery-powered equipment requiring efficient step-down regulation
• Post-regulation for switching power supplies
• General-purpose 3.3 V logic circuit power distribution

Procurement Notes

Verify component authenticity through authorized STMicroelectronics distributors or certified partners. Confirm the specific suffix designation matches the required packaging format, as variations exist between tube and reel configurations. Ensure compliance with RoHS directives relevant to the manufacturing date code. Cross-reference datasheet revisions to confirm pinout consistency before finalizing procurement orders.

Selection Notes

Select this component when a fixed 3.3 V rail is required with up to 950 mA capacity in a compact surface-mount form factor. Evaluate thermal dissipation requirements based on the input voltage differential and load current, as the SOIC-8 package has limited heat sinking capability compared to TO-220 variants. Verify that the minimum input voltage remains above the dropout threshold under all operating conditions.

Part Context

This part belongs to the LD1117 family of low-dropout regulators, which includes adjustable versions and other fixed voltages like 1.2 V, 1.8 V, 2.5 V, and 5.0 V. The 'D' suffix typically denotes the SOIC-8 surface-mount package variant. The series is characterized by NPN pass transistors for high efficiency and tight output voltage tolerance.

Replacement Considerations

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