The part number "LD1117S33TR" refers to a Low Dropout Regulator (LDO). It's made by STMicroelectronics, a well-known semiconductor manufacturer. The "LD1117" series includes several voltage options, and the "S33" indicates the regulator is outputting 3.3V.
Pinout and Detailed Pin Function
The LD1117S33TR is typically available in the TO-220 and SOT-223 packages. I'll provide detailed pinout for the TO-220 package, as this is the most common. Here's a breakdown of the pins:
TO-220 Package Pinout (3 Pins) Pin Number Pin Name Function Description Pin 1 Adj (Adjust) The adjustable input for the regulator; can be used to adjust output voltage with an external resistor divider (if it's not the fixed version). For the LD1117S33TR, this pin is typically not used since it's a fixed 3.3V version. Pin 2 Vout (Output Voltage) This pin provides the regulated output voltage, which is 3.3V for the LD1117S33TR model. Pin 3 Vin (Input Voltage) This is the input voltage pin. It requires a voltage higher than 3.3V (typically between 4.5V and 12V depending on the current load). SOT-223 Package Pinout (3 Pins) Pin Number Pin Name Function Description Pin 1 Adj (Adjust) Same function as in TO-220, used for adjusting the output voltage. For the fixed version, this pin may not be used. Pin 2 Vout (Output Voltage) The regulated output pin, 3.3V output for this model. Pin 3 Vin (Input Voltage) Input voltage pin, requiring a voltage higher than 3.3V.Circuit Principle and Operation of LD1117S33TR
The LD1117S33TR operates based on the principles of a Low Dropout Regulator (LDO), meaning it can regulate output voltage with a very small difference between input and output voltage (as low as 1.1V for this model).
Input Voltage (Vin): The input voltage must be higher than the desired output voltage (3.3V) by at least 1.1V to maintain regulation. So the minimum input is typically 4.4V.
Adjust Pin (Adj): For the fixed 3.3V version (LD1117S33TR), this pin is not used, but in adjustable versions, this pin allows the user to set the output voltage by connecting a voltage divider circuit.
Output Voltage (Vout): This pin outputs a regulated voltage of 3.3V (fixed version) to power circuits.
Dropout Voltage: The dropout voltage for this LDO is typically around 1.1V, which is the minimum difference between input and output for proper regulation.
FAQs
1. What is the output voltage of the LD1117S33TR?
The output voltage is 3.3V.2. What is the minimum input voltage required for the LD1117S33TR to regulate?
The minimum input voltage should be 4.4V to ensure proper regulation, considering the dropout voltage.3. How many pins does the LD1117S33TR have?
The LD1117S33TR has 3 pins in its standard packages (TO-220, SOT-223).4. Can the LD1117S33TR be used for higher output voltages?
No, the LD1117S33TR is a fixed 3.3V LDO. For other output voltages, you would need to choose a different variant from the LD1117 family.5. Can I adjust the output voltage of the LD1117S33TR?
No, the LD1117S33TR is a fixed output version at 3.3V. Adjustable versions are available in the LD1117 series.6. What is the dropout voltage of the LD1117S33TR?
The typical dropout voltage for the LD1117S33TR is 1.1V.7. What is the maximum input voltage for the LD1117S33TR?
The maximum input voltage for the LD1117S33TR is 15V.8. Can I use the LD1117S33TR for powering high current devices?
The LD1117S33TR can supply up to 800mA of current, so it is suitable for many low-power applications but may not be ideal for high current devices.9. What is the package type for the LD1117S33TR?
The LD1117S33TR is available in both TO-220 and SOT-223 packages.10. What is the typical application for the LD1117S33TR?
It is typically used in voltage regulation for low-power electronic circuits, especially those requiring a stable 3.3V power supply.11. Can the LD1117S33TR be used in battery-powered applications?
Yes, as long as the input voltage is above the dropout voltage (e.g., 4.4V or more), it can be used in battery-powered circuits.12. What is the thermal resistance of the LD1117S33TR?
The thermal resistance for the LD1117S33TR in a TO-220 package is typically 50°C/W.13. How do I connect the LD1117S33TR in a circuit?
Connect the input voltage (Vin) to pin 3, the output voltage (Vout) to pin 2, and leave pin 1 (Adj) unused in the fixed version.14. Is there any protection for overcurrent or overheating in the LD1117S33TR?
Yes, the LD1117S33TR includes overcurrent protection and thermal shutdown features to prevent damage to the device.15. Can I use the LD1117S33TR with a capacitor on the output?
Yes, it is recommended to place a capacitor (typically 10µF or higher) on the output to improve stability.16. What is the quiescent current of the LD1117S33TR?
The quiescent current (the current the LDO consumes while regulating) is typically very low, around 5mA.17. Does the LD1117S33TR have any special requirements for input or output capacitors?
It is recommended to use capacitors on both the input and output. A 10µF output capacitor and a 1µF input capacitor are commonly used for stable operation.18. Can the LD1117S33TR be used for powering logic circuits?
Yes, the LD1117S33TR is suitable for powering low-voltage logic circuits, especially where 3.3V is required.19. What are the key features of the LD1117S33TR?
Key features include low dropout voltage (1.1V), fixed 3.3V output, overcurrent protection, and thermal shutdown.20. What is the recommended operating temperature range for the LD1117S33TR?
The recommended operating temperature range for the LD1117S33TR is -40°C to 125°C.Let me know if you need any more details!