Overview
The LD1117ASTR is a low dropout voltage regulator produced by STMicroelectronics. This component is part of the LD1117A series, which is known for its high performance and versatility in power management applications. The LD1117ASTR is available in the SOT-223 package and is designed to provide a stable output voltage with minimal dropout voltage. It is suitable for a wide range of electronic systems requiring reliable and efficient voltage regulation.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Output Voltage | 1.2 V, 1.8 V, 3.3 V (Fixed), Adjustable (VREF = 1.25 V) | V |
| Output Current | Up to 1 A | A |
| Dropout Voltage | 1.15 V typ. @ IOUT = 1 A, 25 °C | V |
| Quiescent Current | 5 mA typ. @ 25 °C | mA |
| Supply Voltage Rejection | 80 dB typ. @ 25 °C | dB |
| Operating Temperature Range | 0 °C to 125 °C | °C |
| Thermal Resistance Junction-Case | 15 °C/W (SOT-223) | °C/W |
| Thermal Resistance Junction-Ambient | 110 °C/W (SOT-223) | °C/W |
| Package | SOT-223 |
Key Features
- Low Dropout Voltage: The LD1117ASTR features a low dropout voltage of 1.15 V typical at 1 A output current, ensuring high efficiency in power conversion.
- High Output Current: Capable of delivering up to 1 A of output current, making it suitable for a variety of power-intensive applications.
- Fixed and Adjustable Output Voltages: Available in fixed output voltages (1.2 V, 1.8 V, 3.3 V) and an adjustable version with a reference voltage of 1.25 V.
- Internal Current and Thermal Limiting: Built-in current and thermal limiting protect the device from overcurrent and overheating conditions.
- High Supply Voltage Rejection: Offers high supply voltage rejection of 80 dB typical at 25 °C, ensuring stable output voltage despite input voltage variations.
- Compact Packaging: The SOT-223 package optimizes thermal characteristics and offers significant space savings.
Applications
The LD1117ASTR is versatile and can be used in a variety of applications, including:
- Power Supplies: For building efficient and stable power supplies in electronic devices.
- Embedded Systems: In microcontroller-based systems where stable voltage regulation is critical.
- Automotive Electronics: Due to its robust thermal performance and wide operating temperature range.
- Industrial Control Systems: Where reliable voltage regulation is essential for consistent performance.
- Consumer Electronics: In devices such as smartphones, tablets, and other portable electronics.
Q & A
- What is the maximum output current of the LD1117ASTR?
The LD1117ASTR can deliver up to 1 A of output current. - What are the available fixed output voltages for the LD1117ASTR?
The fixed output voltages available are 1.2 V, 1.8 V, and 3.3 V. - What is the typical dropout voltage of the LD1117ASTR at 1 A output current?
The typical dropout voltage is 1.15 V at 1 A output current and 25 °C. - What is the quiescent current of the LD1117ASTR?
The quiescent current is typically 5 mA at 25 °C. - What is the operating temperature range of the LD1117ASTR?
The operating temperature range is from 0 °C to 125 °C. - What package types are available for the LD1117ASTR?
The LD1117ASTR is available in the SOT-223 package. - Does the LD1117ASTR have built-in current and thermal limiting?
Yes, it has internal current and thermal limiting to protect the device. - What is the supply voltage rejection of the LD1117ASTR?
The supply voltage rejection is typically 80 dB at 25 °C. - Is the LD1117ASTR RoHS compliant?
Yes, the LD1117ASTR is RoHS compliant and comes in ECOPACK® packages. - How can the output voltage be adjusted in the adjustable version of the LD1117ASTR?
The output voltage can be adjusted using the formula VOUT = VREF (1 + R2 / R1), where VREF is the reference voltage between the OUT and ADJ pins.
