Overview
The STMicroelectronics LD1117DT50CTR is a low-dropout (LDO) linear voltage regulator designed to provide a stable 5 V output from a higher input voltage with excellent load regulation and low noise. It is part of the LD1117 series, optimized for applications requiring efficient voltage regulation, thermal stability, and compact packaging.

Voltage Regulation and Output
The LD1117DT50CTR provides a fixed output voltage of 5 V with a typical output current capability of up to 800 mA. It maintains excellent line and load regulation, ensuring consistent voltage delivery even under fluctuating input conditions or varying load currents. The device features a typical dropout voltage of 1.1 V at full load, allowing operation with a minimal input-output differential.

Input Voltage and Operating Range
The regulator operates with an input voltage range of 6.5 V to 15 V, accommodating standard power supply rails commonly used in embedded systems, consumer electronics, and industrial applications. The device ensures proper operation across the full industrial temperature range of –40°C to +125°C.

Output Current and Protection Features
The LD1117DT50CTR supports output currents up to 800 mA, suitable for powering microcontrollers, logic circuits, sensors, and other peripheral devices. It incorporates internal thermal shutdown, current limiting, and safe area protection, enhancing device reliability and protecting both the regulator and the load from abnormal operating conditions.

Load and Line Regulation
The device exhibits tight load regulation (typically 0.2% for 10 mA to 800 mA load changes) and line regulation (typically 0.2% for 7 V to 15 V input variation), ensuring precise and stable voltage output in dynamic environments. This makes it particularly suitable for sensitive analog and digital circuits requiring low ripple and accurate voltage levels.

Noise and Ripple Characteristics
The LD1117DT50CTR has low output noise and high power supply rejection ratio (PSRR), minimizing voltage ripple and preventing high-frequency noise from propagating to downstream circuitry. Typical ripple rejection is around 70 dB at 1 kHz, providing clean power for analog and digital systems.

Thermal Performance
The LDO features internal thermal protection and a junction-to-ambient thermal resistance of approximately 50°C/W in the TO-220 package, enabling reliable operation at high load currents with appropriate heat sinking. The device’s thermal shutdown ensures safe operation in the event of excessive temperature.

Package and Mounting
The LD1117DT50CTR is available in a TO-220 package, providing ease of mounting and enhanced heat dissipation through its metal tab. The package is designed for both through-hole and high-power applications, supporting additional heatsinks when needed.

Applications
This regulator is widely used in embedded systems, microcontroller-based circuits, power supply modules, industrial instrumentation, and consumer electronics where stable 5 V operation is required. It is ideal for systems requiring compact voltage regulation, high reliability, and low output noise.

Key Electrical Specifications

* Output Voltage: 5 V ±1% typical
* Maximum Output Current: 800 mA
* Dropout Voltage: 1.1 V at 800 mA
* Input Voltage Range: 6.5 V to 15 V
* Operating Temperature Range: –40°C to +125°C
* Load Regulation: 0.2% typical
* Line Regulation: 0.2% typical
* PSRR: 70 dB at 1 kHz
* Package: TO-220

Performance Highlights
The LD1117DT50CTR combines low dropout operation, high current capability, and robust protection features, making it a reliable choice for powering sensitive electronics. Its low noise and precise voltage regulation ensure optimal performance in both analog and digital applications.