The part number "NCP1117LPST33T3G" belongs to ON Semiconductor (ON Semi), a leading provider of semiconductor components.
This specific part is a low dropout (LDO) voltage regulator, with an output voltage of 3.3V, designed for efficient power regulation in various electronic applications. It is packaged in a SOT-223 form factor, which is a surface-mount package.
Pinout and Pin Function Details:
The NCP1117LPST33T3G has 3 pins (as the SOT-223 package is a 3-pin configuration), and here is the detailed pin function specification:
Pin Number Pin Name Pin Function Description 1 Adj Adjustable input for setting output voltage (not used in this specific 3.3V version). For versions that are adjustable, this pin would connect to a resistive divider to set the desired output voltage. 2 Vout The regulated output voltage. For the NCP1117LPST33T3G, this is 3.3V. It supplies power to your load device. 3 Vin The input voltage. Typically, this is a voltage higher than 3.3V, which the regulator will step down to 3.3V.Circuit Principle:
The NCP1117LPST33T3G operates as a low-dropout regulator, which means it can regulate the output voltage with a small difference between the input and output voltages (typically as low as 1.1V). It uses an internal pass transistor (typically a PMOS transistor) to regulate the output voltage. The feedback mechanism ensures the output stays stable at 3.3V, even with varying input voltages and load conditions.Common FAQ about NCP1117LPST33T3G:
Q: What is the output voltage of the NCP1117LPST33T3G? A: The output voltage of the NCP1117LPST33T3G is 3.3V. Q: What is the maximum input voltage for the NCP1117LPST33T3G? A: The maximum input voltage should be 15V, but to ensure proper regulation, it is recommended to keep the input voltage between 5V and 12V. Q: What is the typical dropout voltage for the NCP1117LPST33T3G? A: The typical dropout voltage is about 1.1V, meaning the input voltage needs to be at least 4.4V for proper regulation. Q: Can the NCP1117LPST33T3G handle high current loads? A: The NCP1117LPST33T3G can typically handle up to 800mA of output current under proper cooling conditions. Q: How do I use the "Adj" pin if I want to set a different output voltage? A: If you are using a version of the NCP1117 that is adjustable, you would use the "Adj" pin to create a voltage divider between this pin and ground to set the output voltage according to the formula specified in the datasheet. Q: Can the NCP1117LPST33T3G be used for battery-powered devices? A: Yes, as a low-dropout regulator, the NCP1117LPST33T3G is ideal for use in battery-powered devices where maintaining a stable 3.3V output is critical, even with limited input voltage. Q: What is the thermal resistance for the NCP1117LPST33T3G in a typical application? A: The thermal resistance from junction to ambient is typically 50°C/W. Q: How does the NCP1117LPST33T3G protect itself from overheating? A: The NCP1117LPST33T3G has built-in thermal shutdown to prevent damage from overheating by disabling the output if the junction temperature exceeds a certain limit. Q: Does the NCP1117LPST33T3G require external capacitor s? A: Yes, external input and output capacitors are recommended for stable operation. Typically, a 10µF capacitor is used at the output.Q: Can I use the NCP1117LPST33T3G in a circuit with high-frequency noise?
A: The NCP1117LPST33T3G features good rejection of high-frequency noise, but additional filtering might be needed if operating in very noisy environments.Q: What is the quiescent current for the NCP1117LPST33T3G?
A: The typical quiescent current is 5mA, which is the current consumed by the regulator itself when no load is connected.Q: What is the maximum power dissipation of the NCP1117LPST33T3G?
A: The power dissipation is calculated as (Vin - Vout) × Iload. For a higher input voltage, the power dissipation will increase and needs to be considered for thermal management.Q: Is the NCP1117LPST33T3G suitable for automotive applications?
A: Yes, the NCP1117LPST33T3G is rated for a wide temperature range and is suitable for many automotive power regulation applications.Q: What is the output voltage tolerance of the NCP1117LPST33T3G?
A: The output voltage tolerance is typically ±2%.Q: Can I use the NCP1117LPST33T3G to regulate voltages other than 3.3V?
A: The NCP1117LPST33T3G is fixed at 3.3V; however, ON Semiconductor offers similar regulators with different output voltages.Q: How can I ensure the stability of the output voltage?
A: To ensure stability, it's important to use proper input and output capacitors as recommended in the datasheet.Q: What is the recommended PCB layout for the NCP1117LPST33T3G?
A: The datasheet provides a recommended PCB layout that includes ground planes, short trace lengths, and proper decoupling capacitor placement to minimize noise and improve performance.Q: What happens if the input voltage drops below 3.3V?
A: If the input voltage drops below 3.3V, the NCP1117LPST33T3G will no longer be able to regulate the output voltage properly, and the output voltage will follow the input voltage.Q: What is the output noise level of the NCP1117LPST33T3G?
A: The NCP1117LPST33T3G has low output noise, typically less than 30µVRMS (under 10Hz to 100kHz bandwidth).Q: Can I use the NCP1117LPST33T3G to power sensitive analog circuits?
A: Yes, with its low noise and stable output, the NCP1117LPST33T3G is suitable for powering sensitive analog circuits.