LD1117S50TR - 800mA Low Dropout Positive Regulator | STMicroelectronics
MPN: LD1117S50TR β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.35 | $0.35 |
| 10 | $0.3 | $3.00 |
| 100 | $0.25 | $25.00 |
| 500 | $0.2 | $100.00 |
| 1,000 | $0.18 | $180.00 |
Drop-in alternatives for LD1117S50TR β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
LD1117S33TR
β Drop-Inβ 99,999 In Stock
$0.2 / Unit
View Datasheet βLD1117S12TR
β Drop-Inπ Reference alternative (not in catalog)
LD1117S18TR
β Drop-Inβ 99,999 In Stock
$0.15 / Unit
View Datasheet βAMS1117-5.0
β Drop-Inπ Reference alternative (not in catalog)
NCP1117ST50T3G
β Drop-Inπ Reference alternative (not in catalog)
AP1117-5.0
β Drop-Inπ Reference alternative (not in catalog)
LD1117S50TR Maximum Ratings & Electrical Characteristics
| Output Type | Fixed |
| Output Voltage | 5.0 V |
| Maximum Output Current | 800 mA |
| Input Voltage Range | 6.5 V to 15 V |
| Dropout Voltage | 1.1 V at 800 mA |
| Quiescent Current | 5 mA typical |
| Load Regulation | 0.2% typical |
| Line Regulation | 0.2% typical |
| Thermal Resistance (Junction-to-Ambient) | 50 Β°C/W |
| Operating Temperature Range | -40Β°C to +125Β°C |
| Package | SOT-223 |
| Mounting Type | Surface Mount |
| MSL Level | 1 (unlimited) |
| RoHS Status | Compliant |
| Protection Features | Current limiting, thermal shutdown |
LD1117S50TR Pin Configuration
| Pin 1 | GND β Ground |
| Pin 2 | VOUT β Regulated 5V output |
| Pin 3 | VIN β Input supply voltage |
| Pin Tab | VOUT β Exposed tab connected to output for thermal dissipation |
Safe Operating Area (SOA) & Thermal Characteristics
No official SOA curve available for this component. Always operate within absolute maximum ratings specified in the datasheet. Ensure adequate cooling and derate as needed.
Typical Applications
LD1117S50TR is suitable for 6 applications: Post-Regulation of Switching Power Supplies, Battery-Powered Equipment, Local 5V Rail for Microcontrollers, USB-Powered Devices, Industrial Control Systems, Audio Equipment.
Post-Regulation of Switching Power Supplies
The LD1117S50TR is used to provide a clean, regulated 5V rail after a switching regulator. Its low dropout voltage and low output noise ensure that the downstream circuitry receives a stable supply, reducing ripple and improving performance. In a typical application, the LD1117S50TR is placed after a buck converter that outputs 6.5V to 15V, and it regulates down to 5V with a maximum current of 800mA. The low dropout voltage of 1.1V allows efficient operation even when the input is only slightly above the output, minimizing power dissipation. The device's internal current limiting and thermal shutdown protect the system under fault conditions. Compared to using a switching regulator alone, the LDO provides a cleaner output with lower noise, which is critical for analog and RF circuits. The SOT-223 package with exposed tab allows for adequate thermal dissipation, making it suitable for continuous operation at moderate loads.
Recommended
Battery-Powered Equipment
In battery-powered devices, the LD1117S50TR provides a stable 5V rail from a battery voltage that may vary between 6.5V and 15V. Its low quiescent current of 5mA helps extend battery life, and the low dropout voltage ensures efficient use of the battery's energy as it discharges. For example, in a portable instrument powered by a 9V battery, the LD1117S50TR regulates the voltage down to 5V for the microcontroller and sensors. The device's thermal shutdown and current limiting protect the battery and the load from overcurrent and overheating. The SOT-223 package is compact and suitable for space-constrained designs. The low dropout voltage allows the regulator to continue providing a stable output even when the battery voltage drops close to 6.5V, maximizing the usable battery capacity. This makes the LD1117S50TR an excellent choice for portable and handheld devices.
Recommended
Local 5V Rail for Microcontrollers
The LD1117S50TR is ideal for providing a local 5V rail to microcontrollers and digital logic circuits. Its fixed 5V output is compatible with standard logic levels, and the low dropout voltage allows it to operate from a 6.5V input with minimal power loss. In a typical design, the LD1117S50TR is placed near the microcontroller to provide a clean, regulated supply, reducing noise and ensuring reliable operation. The device's fast transient response helps maintain stable voltage during sudden load changes, such as when the microcontroller wakes from sleep mode. The SOT-223 package is easy to solder and fits well in compact PCB layouts. The internal current limiting and thermal shutdown provide additional protection for the microcontroller and the regulator itself. This application is common in industrial control, consumer electronics, and IoT devices.
Recommended
USB-Powered Devices
The LD1117S50TR can be used in USB-powered devices to provide a stable 5V rail from the USB bus voltage. Although USB provides 5V, the actual voltage can vary between 4.75V and 5.25V, and the LD1117S50TR can regulate this to a precise 5V output. However, the input voltage range of 6.5V to 15V means that the LD1117S50TR cannot be directly powered from a standard 5V USB supply. Instead, it is often used in devices that have a higher input voltage, such as a boost converter that steps up the USB voltage to 6.5V or higher. In such designs, the LD1117S50TR provides a clean, regulated 5V rail for the main circuitry. The low dropout voltage ensures efficient operation, and the thermal shutdown protects the device in case of overcurrent. This application is common in USB hubs, chargers, and other peripherals.
Recommended
Industrial Control Systems
In industrial control systems, the LD1117S50TR provides a reliable 5V rail for sensors, microcontrollers, and communication interfaces. Its wide input voltage range of 6.5V to 15V allows it to be powered from common industrial supply rails such as 12V or 24V (with appropriate stepping down). The device's robust protection features, including current limiting and thermal shutdown, ensure reliable operation in harsh environments. The low dropout voltage minimizes power dissipation, reducing the need for large heatsinks. The SOT-223 package is rugged and suitable for industrial PCB assemblies. The LD1117S50TR's stable output voltage and low noise make it ideal for analog sensor interfaces and precision measurement circuits. This application is common in factory automation, process control, and building management systems.
Recommended
Audio Equipment
The LD1117S50TR can be used in audio equipment to provide a clean 5V rail for audio codecs, amplifiers, and digital signal processors. Its low output noise and stable regulation help minimize audio distortion and interference. In a typical audio application, the LD1117S50TR is used to power the analog and digital sections of an audio codec, ensuring that the supply voltage is free from ripple and noise. The low dropout voltage allows efficient operation from a 6.5V input, which is common in battery-powered audio devices. The device's fast transient response ensures that the voltage remains stable during dynamic audio peaks. The SOT-223 package is compact and suitable for portable audio devices. The LD1117S50TR's thermal shutdown protects the device from overheating during prolonged high-power operation. This application is common in portable music players, headphones, and audio interfaces.
Recommended
Recommended Products Summary
Engineering reference data for LD1117S50TR β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LD1117S33TR | AMS1117-5.0 | NCP1117ST50T3G |
|---|---|---|---|---|
| Package | SOT-223 | SOT-223 | SOT-223 | SOT-223 |
| Brand | STMicroelectronics | STMicroelectronics | Advanced Monolithic Systems | onsemi |
| Output Voltage | 5.0V | 3.3V | 5.0V | 5.0V |
| Maximum Output Current | 800mA | 800mA | 1A | 1A |
| Dropout Voltage | 1.1V at 800mA | 1.1V at 800mA | 1.1V at 800mA | 1.1V at 800mA |
| Quiescent Current | 5mA | 5mA | 5mA | 5mA |
| Input Voltage Range | 6.5V to 15V | 6.5V to 15V | 6.5V to 15V | 6.5V to 15V |
| RoHS Compliant | Yes | Yes | Yes | Yes |
Key Differentiators
- Low dropout voltage of 1.1V at 800mA (vs AMS1117-5.0)
- Fixed 5V output with 800mA capability (vs LD1117S33TR)
- Wide input voltage range of 6.5V to 15V (vs NCP1117ST50T3G)
Design Notes
The LD1117S50TR in SOT-223 package has a junction-to-ambient thermal resistance of 50Β°C/W. At maximum output current of 800mA and a typical dropout of 1.1V, the power dissipation is approximately 0.88W, resulting in a temperature rise of 44Β°C above ambient. For reliable operation, ensure adequate copper area on the PCB connected to the exposed tab. For ambient temperatures above 70Β°C, consider derating the output current or adding a heatsink.
Place input and output capacitors as close to the LD1117S50TR pins as possible. A 10uF ceramic capacitor on the input and a 10uF ceramic capacitor on the output are recommended for stability. The output capacitor must have an ESR in the range of 0.1 to 10 ohms for stable operation. Connect the exposed tab to a large copper pour to enhance thermal dissipation.
Do not exceed the maximum input voltage of 15V. Ensure the input voltage is at least 6.5V to maintain regulation. The LD1117S50TR is not designed for parallel operation; do not connect multiple regulators in parallel to increase output current. Also, avoid using the device in applications that require AEC-Q100 qualification, as it is not automotive-grade.
Compliance Information
RoHS compliant per STMicroelectronics product page. Not AEC-Q100 qualified. Lead-free per datasheet.
