LD1117S18TR - 1.8V Fixed 800mA LDO Regulator | STMicroelectronics
料号： LD1117S18TR ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $0.35 | $0.35 |
| 10 | $0.28 | $2.80 |
| 100 | $0.22 | $22.00 |
| 500 | $0.18 | $90.00 |
| 1,000 | $0.15 | $150.00 |
LD1117S18TR 概述
An LDO (Low-Dropout) linear regulator is a type of voltage regulator that maintains a stable output voltage even when the input voltage is very close to the output voltage. Unlike standard linear regulators, LDOs can operate with a small dropout voltage, typically less than 1V, which improves efficiency and allows for lower input voltages. In the hierarchy of power management, an LDO is a type of linear regulator, which is a type of voltage regulator, which is a type of power management IC. LDOs are essential in applications where low noise and simplicity are prioritized over efficiency, such as in battery-powered devices and analog circuits.
Key features of the LD1117S18TR include a fixed 1.8V output voltage, a dropout voltage of 1.1V at 800mA, and a quiescent current of 5mA. The device also includes internal current limiting and thermal shutdown protection, ensuring safe operation under fault conditions. The SOT-223 package offers a compact footprint with a thermal resistance of 50°C/W, allowing for moderate power dissipation without external heatsinking.
The LD1117S18TR is designed with a PNP pass transistor architecture, which provides a low dropout voltage and stable operation. The device is stable with a wide range of output capacitors, including ceramic capacitors, which simplifies the design and reduces component count. The internal current limiting and thermal shutdown features protect the regulator and the load from damage due to overcurrent or overtemperature conditions.
Typical applications for the LD1117S18TR include powering microcontrollers, FPGAs, and other digital ICs that require a stable 1.8V supply. It is also used in battery-powered devices, such as portable electronics and IoT devices, where low quiescent current and small size are important. Additionally, the device is suitable for post-regulation in switching power supplies to reduce ripple and noise.
When designing with the LD1117S18TR, ensure that the input voltage is at least 1.1V above the output voltage to maintain regulation. The output capacitor should be placed close to the output pin to ensure stability. For higher current applications, consider the power dissipation and use appropriate PCB copper area to keep the junction temperature within safe limits.
直接替换替代料： LD1117S18TR ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
本系列中的变体
可与以下型号直接替换的同系列型号： LD1117S18TR （相同外形与封装尺寸） ——差异在于 Output Voltage, Input Voltage Range, Line Regulation, Load Regulation, Dropout Voltage.
快速对比工具——选择替代料号进行并排对比：
LD1117S33TR
✅ 直接替换 ⚠️ 规格未核验✓ 有现货
$0.2 / 个
查看数据手册 →LD1117S12TR
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
LD1117S25TR
✅ 直接替换 ⚠️ 规格未核验✓ 有现货
$0.18 / 个
查看数据手册 →AMS1117-1.8
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
NCP1117ST18T3G
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
AP1117-18
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
LD1117S18TR 最大额定值与电气特性
| 输出类型 | Fixed |
| 输出电压 | 1.8 V |
| 最大输出电流 | 800 mA |
| 输入电压范围 | 2.5 V to 15 V |
| 压差电压 | 1.1 V at 800 mA |
| 静态电流 | 5 mA |
| Line Regulation | 0.2% (typical) |
| Load Regulation | 0.4% (typical) |
| 热阻，结到环境 | 50 °C/W |
| 工作温度范围 | -40°C to +125°C |
| 封装 | SOT-223 |
| 安装类型 | Surface Mount |
| MSL 等级 | 1 (unlimited) |
| RoHS 状态 | Compliant |
| 使能引脚 | No |
LD1117S18TR 引脚配置
| 引脚 1 | GND — Ground |
| 引脚 2 | VOUT — Regulated output voltage (1.8V) |
| 引脚 3 | VIN — Input supply voltage |
| 引脚 4 | TAB — Exposed pad, connected to VOUT |
典型应用
LD1117S18TR 适用于 6 应用s: Microcontroller Power Supply, FPGA Core Voltage, Battery-Powered IoT Devices, Post-Regulation in Switching Power Supplies, Industrial Control Systems, Consumer Electronics.
Microcontroller Power Supply
The LD1117S18TR provides a stable 1.8V supply for microcontrollers that operate at this voltage, such as STM32L series. Its low dropout voltage and 800mA output current ensure reliable operation even when the input voltage is close to 1.8V. The SOT-223 package is compact and suitable for space-constrained designs. The low quiescent current of 5mA helps extend battery life in portable applications. The device's thermal shutdown protection prevents damage from overheating, ensuring long-term reliability.
推荐
FPGA Core Voltage
Many FPGAs require a 1.8V core voltage, and the LD1117S18TR can provide this with low noise and good regulation. The device's 800mA output current is sufficient for small to medium FPGAs. The low dropout voltage allows operation from a 3.3V rail with adequate headroom. The SOT-223 package is easy to solder and fits on standard PCB footprints. The internal current limiting protects the FPGA from overcurrent conditions. The device's thermal shutdown ensures safe operation under high ambient temperatures.
推荐
Battery-Powered IoT Devices
The LD1117S18TR is ideal for battery-powered IoT devices that require a stable 1.8V supply. Its low quiescent current of 5mA helps conserve battery power, extending device runtime. The wide input voltage range of 2.5V to 15V allows operation from various battery configurations, such as two AA batteries or a single lithium-ion cell. The SOT-223 package is compact and lightweight, making it suitable for wearable and portable devices. The device's thermal shutdown and current limiting provide protection in harsh environments.
推荐
Post-Regulation in Switching Power Supplies
The LD1117S18TR can be used as a post-regulator after a switching power supply to reduce ripple and noise. Its low dropout voltage and high PSRR ensure a clean 1.8V output. The device's 800mA output current is sufficient for many digital loads. The SOT-223 package allows for easy integration into existing power supply designs. The internal current limiting and thermal shutdown provide additional protection. The device's stability with ceramic capacitors simplifies the output filter design.
推荐
Industrial Control Systems
The LD1117S18TR is suitable for industrial control systems that require a reliable 1.8V supply for logic circuits and sensors. Its wide input voltage range and robust protection features make it suitable for harsh industrial environments. The device's operating temperature range of -40°C to +125°C ensures reliable operation in extreme conditions. The SOT-223 package is rugged and can withstand vibration and thermal cycling. The low dropout voltage allows operation from a 3.3V rail with minimal power loss.
推荐
Consumer Electronics
The LD1117S18TR is used in consumer electronics such as set-top boxes, routers, and gaming consoles to provide a stable 1.8V supply for various ICs. Its low cost and small footprint make it ideal for high-volume production. The device's low quiescent current helps meet energy efficiency standards. The SOT-223 package is compatible with standard reflow soldering processes. The device's thermal shutdown and current limiting protect the product from damage due to faults.
推荐
推荐产品汇总
工程参考数据： LD1117S18TR ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | LD1117S33TR | AMS1117-1.8 | NCP1117ST18T3G |
|---|---|---|---|---|
| Package | SOT-223 | SOT-223 | SOT-223 | SOT-223 |
| Brand | STMicroelectronics | STMicroelectronics | Advanced Monolithic Systems | onsemi |
| Output Voltage | 1.8V | 3.3V | 1.8V | 1.8V |
| 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 | 2.5V to 15V | 2.5V to 15V | 2.5V to 15V | 2.5V to 15V |
| Enable Pin | No | No | No | No |
关键差异点
- Fixed 1.8V output with 800mA capability （对比 AMS1117-1.8)
- STMicroelectronics quality and reliability （对比 AP1117-18)
- Wide input voltage range （对比 NCP1117ST18T3G)
设计说明
The LD1117S18TR in SOT-223 has a thermal resistance of 50°C/W. At maximum output current of 800mA and a dropout voltage of 1.1V, power dissipation is approximately 0.88W, resulting in a temperature rise of 44°C above ambient. Ensure adequate PCB copper area for heat dissipation, especially in high ambient temperature environments.
Place input and output capacitors close to the respective pins. A 10uF tantalum or ceramic capacitor on the input and a 10uF capacitor on the output are recommended for stability. The SOT-223 package has a large tab connected to VOUT, which should be soldered to a large copper pad for thermal and electrical performance.
Do not exceed the maximum input voltage of 15V. Ensure the input voltage is at least 1.1V above the output voltage to maintain regulation. The device does not have an enable pin, so power sequencing must be handled externally if required. Use a capacitor with low ESR on the output to avoid oscillation.
合规信息
RoHS compliant per STMicroelectronics product page. Not AEC-Q100 qualified. Lead-free per datasheet.
