LD1117S50TR - 800mA Low Dropout Positive Regulator | STMicroelectronics
部品番号: LD1117S50TR ✓ 生産中| 数量 | 単価 | 小計 |
|---|---|---|
| 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 |
LD1117S50TR 概要
A low dropout (LDO) regulator is a type of linear voltage regulator that can maintain a regulated output voltage even when the input voltage is very close to the output voltage. This is achieved by using a pass transistor that operates in the saturation region, minimizing the voltage drop across the regulator. LDO regulators are essential in power management systems where efficiency and noise are critical, such as in battery-powered devices, automotive electronics, and industrial control systems. They are part of the broader category of voltage regulators, which also includes switching regulators and charge pumps, each with distinct trade-offs in efficiency, noise, and complexity.
Key features of the LD1117S50TR include a low dropout voltage of 1.1V at 800mA, a typical quiescent current of 5mA, and a load regulation of 0.2% typical. The device also includes internal current limiting and thermal shutdown protection, ensuring safe operation under fault conditions. The SOT-223 package offers a thermal resistance of 50°C/W (junction-to-ambient), allowing for moderate power dissipation without external heatsinking in many applications.
The LD1117S50TR utilizes a PNP pass transistor architecture, which provides a low dropout voltage and stable operation. The internal bandgap reference ensures accurate output voltage regulation across temperature and load variations. The device is designed to be stable with a wide range of output capacitors, including ceramic capacitors, which simplifies the design and reduces the overall solution size.
Typical applications include post-regulation of switching power supplies, battery-powered equipment, and as a local 5V rail for microcontrollers, sensors, and analog circuits. The fixed 5V output is ideal for logic circuits and USB-powered devices. The low dropout voltage allows efficient operation even when the input voltage is only slightly above the output, maximizing battery life in portable applications.
When designing with the LD1117S50TR, it is important to ensure adequate input-to-output voltage headroom to maintain regulation under all load conditions. The input and output capacitors should be placed close to the device pins to minimize parasitic inductance and ensure stability. The exposed tab of the SOT-223 package should be connected to a copper pour to enhance thermal dissipation, especially when operating at high load currents.
ドロップイン代替品: LD1117S50TR — 同一パッケージでピン互換。PCBの作り直しが必要な異なるパッケージの部品は除外されています。
このシリーズのバリエーション
同一シリーズでドロップイン互換のモデル: LD1117S50TR （同一形状・フットプリント） — 相違点: Input Voltage Range, Line Regulation, Load Regulation, Output Voltage, Dropout Voltage.
クイック比較ツール — 並列比較する代替部品を選択:
LD1117S33TR
✅ ドロップイン ⚠️ 仕様未検証✓ 在庫あり
$0.2 / 個
データシートを見る →LD1117S12TR
✅ ドロップイン ⚠️ 仕様未検証📋 参考代替品（カタログ未掲載）
LD1117S18TR
✅ ドロップイン ⚠️ 仕様未検証✓ 在庫あり
$0.15 / 個
データシートを見る →AMS1117-5.0
✅ ドロップイン ⚠️ 仕様未検証📋 参考代替品（カタログ未掲載）
NCP1117ST50T3G
✅ ドロップイン ⚠️ 仕様未検証📋 参考代替品（カタログ未掲載）
AP1117-5.0
✅ ドロップイン ⚠️ 仕様未検証📋 参考代替品（カタログ未掲載）
LD1117S50TR 最大定格＆電気的特性
| 出力タイプ | Fixed |
| 出力電圧 | 5.0 V |
| 最大出力電流 | 800 mA |
| 入力電圧範囲 | 6.5 V to 15 V |
| ドロップアウト電圧 | 1.1 V at 800 mA |
| 静止電流 | 5 mA typical |
| Load Regulation | 0.2% typical |
| Line Regulation | 0.2% typical |
| 熱抵抗、接合-周囲間 | 50 °C/W |
| 動作温度範囲 | -40°C to +125°C |
| パッケージ | SOT-223 |
| 実装タイプ | Surface Mount |
| MSLレベル | 1 (unlimited) |
| RoHS ステータス | Compliant |
| Protection Features | Current limiting, thermal shutdown |
LD1117S50TR ピン構成
| ピン 1 | GND — Ground |
| ピン 2 | VOUT — Regulated 5V output |
| ピン 3 | VIN — Input supply voltage |
| ピン Tab | VOUT — Exposed tab connected to output for thermal dissipation |
主な用途
LD1117S50TR の用途: 6 件s: 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.
おすすめ
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.
おすすめ
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.
おすすめ
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.
おすすめ
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.
おすすめ
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.
おすすめ
おすすめ製品の概要
エンジニアリング参考データ: LD1117S50TR — 比較、設計ガイダンス、コンプライアンス情報。
選定ガイド
代替品との比較
| パラメータ | この製品 | 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 |
主な差別化要因
- 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)
設計ノート
The LD1117S50TR in SOT-223 package has a junction-to-ambient thermal resistance of 50°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 44°C above ambient. For reliable operation, ensure adequate copper area on the PCB connected to the exposed tab. For ambient temperatures above 70°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.
コンプライアンス情報
RoHS compliant per STMicroelectronics product page. Not AEC-Q100 qualified. Lead-free per datasheet.
