The LD1117S50TR is a Low Dropout Regulator (LDO) voltage regulator manufactured by STMicroelectronics. The part number “LD1117S50TR” indicates a specific LDO regulator that outputs 5V with a 1A current capability. It typically comes in the SOT-223 package (for the "S" suffix). This package type has 5 pins.
Package: SOT-223
Pins: 5 pins (1, 2, 3, 4, and 5).
Pin Function Details:
Pin No Pin Name Pin Function Description 1 VOUT Voltage Output Pin: This pin provides the regulated output voltage, which is 5V in the case of the LD1117S50TR. This is where the stable, low-noise output is supplied to your circuit. 2 GND Ground Pin: This pin connects to the ground of the power supply or circuit. It serves as the reference point for the output voltage. 3 IN Input Voltage Pin: This pin receives the input voltage from the power supply. The input voltage must be higher than the output voltage by at least the dropout voltage of the LDO. 4 ADJ Adjust Pin (optional for adjustable versions): This pin allows for voltage adjustment by using an external resistor divider. However, for fixed versions like LD1117S50TR, this pin is not used. 5 NC No Connection Pin: This pin has no electrical connection in the circuit. It’s typically used for mechanical stability in the package design.Circuit Principle:
The LD1117S50TR is a linear regulator designed to output a constant voltage. It operates by comparing the output voltage to a reference voltage and adjusting the input to maintain this steady output. The device regulates the voltage through a series of transistor s and feedback loops that compensate for variations in input voltage or load conditions.
The Input pin (IN) receives the higher input voltage, which is stepped down to a constant Output voltage (VOUT). The regulator’s functionality is based on the relationship between the VOUT, GND, and the dropout voltage of the regulator. The GND pin serves as the ground reference. If used with an adjustable version, the ADJ pin will allow you to set the output voltage.
FAQ for LD1117S50TR:
1. What is the output voltage of the LD1117S50TR? The LD1117S50TR provides a fixed output voltage of 5V. 2. How many pins does the LD1117S50TR have? The LD1117S50TR has 5 pins. 3. Can the LD1117S50TR regulate voltages higher than 5V? No, the LD1117S50TR is designed for a fixed 5V output. For other output voltages, a different part number or adjustable version must be used. 4. What is the maximum input voltage for the LD1117S50TR? The maximum input voltage is typically 15V, but this can depend on the specific conditions and load. Please refer to the datasheet for detailed specifications. 5. What is the dropout voltage for the LD1117S50TR? The dropout voltage is typically around 1.1V, meaning the input voltage must be at least 1.1V higher than the output voltage to maintain stable operation. 6. Can the LD1117S50TR handle loads up to 1A? Yes, the LD1117S50TR is designed to provide a maximum output current of 1A. 7. What package does the LD1117S50TR come in? The LD1117S50TR comes in a SOT-223 package. 8. What is the ground pin for in the LD1117S50TR? The GND pin is the reference point for the output voltage and is connected to the ground of your circuit or power source. 9. Is the ADJ pin used in the LD1117S50TR? No, the ADJ pin is not used in the LD1117S50TR since it is a fixed voltage regulator. 10. What is the typical output current for the LD1117S50TR? The typical output current is up to 1A, depending on the thermal conditions and input voltage. 11. Can I use the LD1117S50TR to power sensitive analog circuits? Yes, the LD1117S50TR provides a low-noise output suitable for powering sensitive analog circuits. 12. What is the role of the NC pin in the LD1117S50TR? The NC pin has no electrical connection and serves for mechanical stability. 13. How do I calculate the input capacitor value for the LD1117S50TR? A typical 10µF ceramic capacitor on the input is recommended for stable operation, but this can vary depending on the specific application. 14. What is the temperature range for the LD1117S50TR? The typical operating temperature range is from -40°C to +125°C. 15. Can the LD1117S50TR be used in automotive applications? Yes, as long as the input voltage and temperature ranges are within the limits specified by the datasheet, the LD1117S50TR can be used in automotive circuits. 16. What happens if the input voltage is too low for the LD1117S50TR? If the input voltage falls below the required dropout voltage, the output voltage will not be regulated and will drop. 17. Can I use the LD1117S50TR for powering a microcontroller? Yes, the LD1117S50TR is a great choice for powering microcontrollers, as it provides a stable 5V output with low noise. 18. What are the typical applications for the LD1117S50TR? Typical applications include power supply circuits for microcontrollers, sensor systems, radios, battery-powered devices, and more. 19. How can I improve the thermal performance of the LD1117S50TR? Use a larger heatsink or improve the PCB layout to dissipate heat more effectively. You can also reduce the power dissipation by ensuring the input voltage is as close as possible to 5V. 20. What is the significance of the SOT-223 package for the LD1117S50TR? The SOT-223 package provides a compact form factor with good thermal dissipation, which is suitable for applications where space and thermal management are important.This explanation provides detailed information about the LD1117S50TR voltage regulator, including its pin functions, circuit operation, and frequently asked questions.
