LD1117D50

Overview

The LD1117D50 is a fixed-output positive linear low-dropout regulator (LDO) manufactured by STMicroelectronics. It provides a fixed 5V output with a maximum continuous current of 800mA. The device operates with a maximum input voltage of 15V and features a typical dropout voltage of 1V at full load. It utilizes an NPN pass transistor for high efficiency, where quiescent current primarily flows into the load. The component includes internal thermal overload and short-circuit current limiting protection. It requires a minimum 10μF output capacitor for stability and offers tight output voltage tolerance within ±1% at 25°C.

Feature Summary

• Fixed 5V output configuration with 800mA current capability
• Low dropout voltage performance utilizing NPN pass transistor technology
• Integrated thermal overload and current limit protection circuits
• High supply voltage rejection ratio ensuring stable regulation

Applications

• General-purpose power supply regulation in electronic circuits
• Battery-powered systems requiring efficient step-down conversion
• Pre-regulation stages for switching power supplies
• Noise-sensitive analog circuit power conditioning

Procurement Notes

Verify the specific package type and suffix codes against official STMicroelectronics documentation to ensure compatibility with your design requirements. Confirm that the LD1117D50 designation aligns with the intended DPAK or similar surface-mount packaging variant available in the market. Cross-reference datasheet revisions to ensure all electrical parameters match your system specifications before finalizing procurement decisions.

Selection Notes

Select this component when a fixed 5V rail is required with moderate current demands up to 800mA. Ensure the input voltage remains within the 15V maximum limit while accounting for dropout voltage constraints. Verify thermal management capabilities based on the expected power dissipation in the chosen package. Consider the need for external capacitors meeting the minimum stability requirements specified in the technical data.

Part Context

This part belongs to the LD1117 family of adjustable and fixed low-dropout positive voltage regulators. The family offers various output voltages including 1.2V, 1.8V, 2.5V, 3.3V, and 5.0V. Devices are available in multiple packages such as SOT-223, DPAK, SO-8, and TO-220 to optimize thermal characteristics and space saving. The series is designed for high efficiency and tight voltage tolerance applications.

Replacement Considerations

Direct pin-to-pin replacements may include other LD1117 variants with different output voltages or adjustable versions like LD1117V. Verify that substitute components maintain the same 800mA current rating, 15V input limit, and compatible package footprint. Check for equivalent thermal protection features and stability requirements regarding output capacitance.