Overview
The LD1117AS18TR is a low drop voltage regulator produced by STMicroelectronics. This device is part of the LD1117A series, which is capable of providing up to 1 A of output current. The LD1117AS18TR specifically offers a fixed output voltage of 1.8 V. It is available in various packages, including SOT-223, DPAK, and TO-220, each optimized for thermal characteristics and space efficiency. The regulator features high efficiency due to its NPN pass transistor and requires only a 10 μF capacitor for stability. It also includes internal current and thermal limits, ensuring reliable operation over a wide temperature range.
Key Specifications
| Parameter | Test Conditions | Min. | Typ. | Max. | Unit |
|---|---|---|---|---|---|
| Output Voltage (VO) | VI = 3.8 V, IO = 10 mA, TJ = 25 °C | 1.764 | 1.8 | 1.836 | V |
| Dropout Voltage (VD) | IO = 1 A, TJ = 25 °C | 1.15 | 1.15 | 1.30 | V |
| Quiescent Current (Id) | VI ≤ 8 V, IO = 0 mA, TJ = 25 °C | 5 | 5 | 10 | mA |
| Output Current (IO) | VI - VO = 5 V, TJ = 25 °C | - | - | 1000 | mA |
| Operating Input Voltage (VI) | IO = 100 mA | - | - | 10 | V |
| Thermal Resistance Junction-Case (RthJC) | SOT-223 | - | 15 | - | °C/W |
| Thermal Resistance Junction-Ambient (RthJA) | SOT-223 | - | 110 | - | °C/W |
| Operating Junction Temperature (TOP) | - | 0 | - | 125 | °C |
Key Features
- Low Dropout Voltage: 1.15 V typical at 1 A output current and 25 °C.
- Very Low Quiescent Current: 5 mA typical at 25 °C.
- High Output Current: Up to 1 A.
- Fixed Output Voltages: Available in 1.2 V, 1.8 V, and 3.3 V versions.
- Adjustable Version: Available with a reference voltage of 1.25 V.
- Internal Current and Thermal Limits: Ensures safe operation.
- Minimal Capacitance Requirement: Only 10 μF capacitor needed for stability.
- Tight Output Voltage Tolerance: ± 2% at 25 °C and ± 4% over the full temperature range.
- High Supply Voltage Rejection: 80 dB typical at 25 °C.
Applications
- Power Supply Systems: Suitable for various power supply applications requiring low dropout voltage and high current output.
- Embedded Systems: Ideal for use in embedded systems where space and thermal efficiency are critical.
- Industrial Automation: Used in industrial automation for reliable voltage regulation.
- Consumer Electronics: Applicable in consumer electronics for efficient power management.
- Automotive Systems: Can be used in automotive systems due to its robust thermal and current limiting features.
Q & A
- What is the maximum output current of the LD1117AS18TR?
The maximum output current of the LD1117AS18TR is up to 1 A.
- What are the available output voltages for the LD1117A series?
The LD1117A series offers fixed output voltages of 1.2 V, 1.8 V, and 3.3 V, as well as an adjustable version.
- What is the typical dropout voltage of the LD1117AS18TR 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 LD1117AS18TR?
The quiescent current is 5 mA typical at 25 °C.
- What is the minimum capacitance required for stability?
Only a 10 μF capacitor is needed for stability.
- What are the available package types for the LD1117AS18TR?
The device is available in SOT-223, DPAK, and TO-220 packages.
- What is the operating junction temperature range of the LD1117AS18TR?
The operating junction temperature range is from 0 °C to 125 °C.
- Does the LD1117AS18TR have internal current and thermal limits?
Yes, the device includes internal current and thermal limits for safe operation.
- What is the supply voltage rejection of the LD1117AS18TR?
The supply voltage rejection is 80 dB typical at 25 °C.
- What is the reference voltage for the adjustable version of the LD1117A?
The reference voltage for the adjustable version is 1.25 V.
