LD1117ADT18TR - 1.8V Fixed 800mA LDO Regulator | STMicroelectronics
料号： LD1117ADT18TR ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $0.45 | $0.45 |
| 10 | $0.38 | $3.80 |
| 100 | $0.3 | $30.00 |
| 500 | $0.25 | $125.00 |
| 1,000 | $0.2 | $200.00 |
LD1117ADT18TR 概述
A low-dropout regulator (LDO) is a type of linear voltage regulator that maintains a constant output voltage even when the input voltage is only slightly higher than the output. Unlike switching regulators, LDOs provide a clean, noise-free output, making them ideal for analog and RF circuits. In the hierarchy of power management, an LDO is a linear regulator, which is a type of voltage regulator, which falls under power management ICs, which are part of the broader semiconductor category. The LD1117ADT18TR is a fixed-output LDO, simplifying design by eliminating the need for external resistor dividers.
Key features of the LD1117ADT18TR include a fixed 1.8V output, 800mA output current capability, and a dropout voltage of 1.1V typical at full load. It also offers internal current limiting and thermal shutdown protection, ensuring safe operation under fault conditions. The device is available in the DPAK package, which provides good thermal performance with a junction-to-ambient thermal resistance of 100°C/W, allowing for moderate power dissipation without external heatsinks.
The LD1117ADT18TR is built on a robust bipolar process, providing excellent line and load regulation. It is designed to be stable with low-ESR ceramic capacitors, making it easy to use in modern designs. The device also features a wide operating temperature range of -40°C to +125°C, suitable for industrial and automotive environments.
Typical applications include powering microcontrollers, FPGAs, and other digital ICs that require a 1.8V rail, as well as providing a clean supply for analog circuits such as op-amps and ADCs. It is also used in battery-powered devices, where its low dropout voltage maximizes battery life.
When designing with the LD1117ADT18TR, ensure that the input voltage is at least 1.1V above the output voltage to maintain regulation. Use a 10µF output capacitor to ensure stability, and place it close to the output pin. The thermal pad of the DPAK package should be connected to a large copper area for effective heat dissipation.
直接替换替代料： LD1117ADT18TR ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
快速对比工具——选择替代料号进行并排对比：
LD1117ADT18TR
✅ 直接替换✓ 有现货
$0.2 / 个
查看数据手册 →LD1117DT18TR
✅ 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）
LD1117ADT18TR 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 | Up to 15 V |
| 压差电压 | 1.1 V at 800 mA |
| Line Regulation | 0.2% (typical) |
| Load Regulation | 0.4% (typical) |
| 静态电流 | 5 mA (typical) |
| 工作温度范围 | -40°C to +125°C |
| 封装 | DPAK (TO-252) |
| 安装类型 | Surface Mount |
| 热阻，结到环境 | 100 °C/W |
| RoHS 状态 | Compliant |
LD1117ADT18TR 引脚配置
| 引脚 1 | GND — Ground |
| 引脚 2 | VOUT — Regulated 1.8V output |
| 引脚 3 | VIN — Input supply voltage |
| 引脚 4 | TAB — Exposed pad, connected to GND |
典型应用
LD1117ADT18TR 适用于 6 应用s: Microcontroller Power Supply, FPGA Core Supply, Battery-Powered Devices, Industrial Control Systems, Audio Equipment, Networking Equipment.
Microcontroller Power Supply
The LD1117ADT18TR provides a stable 1.8V rail for microcontrollers that operate at 1.8V logic levels. Its low dropout voltage ensures efficient operation from a 3.3V or 3.6V battery, and its 800mA output current can handle the peak current demands of the MCU and its peripherals. The low output noise and good line/load regulation ensure reliable operation of the MCU's internal analog peripherals, such as ADCs and comparators. In a typical application, the regulator is placed between the battery and the MCU's VDD pin, with a 10µF output capacitor to maintain stability. The thermal shutdown protection prevents damage during short circuits or excessive load.
推荐
FPGA Core Supply
FPGAs often require a separate 1.8V core supply for their internal logic. The LD1117ADT18TR can deliver up to 800mA, which is sufficient for small to medium FPGAs. Its low dropout voltage allows it to operate from a 2.5V or 3.3V rail, and its low noise output is critical for maintaining signal integrity in high-speed designs. The DPAK package with exposed pad provides good thermal dissipation, essential for continuous operation. In a typical FPGA design, the regulator is placed close to the FPGA's core voltage pins, with multiple decoupling capacitors to minimize voltage ripple. The enable pin (if available) can be used for power sequencing, ensuring the core voltage ramps up before I/O voltage.
推荐
Battery-Powered Devices
The LD1117ADT18TR is ideal for battery-powered devices such as portable electronics, wireless sensors, and wearables. Its low dropout voltage of 1.1V allows the regulator to operate even when the battery voltage drops close to the output voltage, maximizing battery life. The quiescent current of 5mA is relatively low, but for ultra-low-power applications, a regulator with lower quiescent current may be preferred. The device's thermal shutdown and current limiting protect the battery and the load from faults. In a typical battery-powered design, the regulator is connected directly to the battery, with a 1µF input capacitor and a 10µF output capacitor. The low noise output ensures clean power for sensitive analog circuits.
推荐
Industrial Control Systems
In industrial control systems, the LD1117ADT18TR provides a reliable 1.8V supply for sensors, actuators, and control logic. Its wide operating temperature range of -40°C to +125°C makes it suitable for harsh environments. The device's robust protection features, including current limiting and thermal shutdown, ensure reliable operation in the presence of voltage transients and overloads. The DPAK package is easy to solder and provides good thermal performance, even in high-vibration environments. In a typical industrial application, the regulator is used to power a microcontroller or FPGA that controls motors, valves, or other actuators. The low dropout voltage allows it to operate from a 24V bus with a pre-regulator, or directly from a 3.3V rail.
推荐
Audio Equipment
The LD1117ADT18TR can be used in audio equipment to provide a clean 1.8V supply for audio codecs, DACs, and op-amps. Its low output noise and high PSRR (if specified) help minimize hum and noise in the audio signal path. The low dropout voltage ensures stable operation even when the input voltage is close to the output, which is common in battery-powered audio devices. In a typical audio application, the regulator is placed between the battery and the audio codec's analog supply pin, with a 10µF output capacitor and a 0.1µF bypass capacitor for high-frequency noise. The thermal shutdown protection prevents damage during prolonged high-volume operation.
推荐
Networking Equipment
In networking equipment such as routers and switches, the LD1117ADT18TR provides a stable 1.8V supply for PHY chips, switch ICs, and other digital components. Its low dropout voltage allows it to operate from a 3.3V rail, and its 800mA output current can handle the power requirements of multiple ICs. The device's low noise output is important for maintaining signal integrity in high-speed Ethernet interfaces. The DPAK package is suitable for compact PCB designs, and the thermal pad helps dissipate heat generated by continuous operation. In a typical networking application, the regulator is used to power the PHY's digital core, with proper decoupling to minimize voltage ripple.
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推荐产品汇总
工程参考数据： LD1117ADT18TR ——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 | LD1117DT18TR | NCP1117ST18T3G | AP1117-18 |
|---|---|---|---|---|
| Package | DPAK (TO-252) | DPAK (TO-252) | DPAK (TO-252) | DPAK (TO-252) |
| Brand | STMicroelectronics | STMicroelectronics | onsemi | Diodes Incorporated |
| Output Voltage | 1.8V | 1.8V | 1.8V | 1.8V |
| Maximum Output Current | 800mA | 800mA | 1A | 1A |
| Dropout Voltage | 1.1V | 1.2V | 1.1V | 1.1V |
| Input Voltage Range | Up to 15V | Up to 15V | Up to 20V | Up to 18V |
| Quiescent Current | 5mA | 5mA | 5mA | 5mA |
| Operating Temperature Range | -40°C to +125°C | -40°C to +125°C | -40°C to +125°C | -40°C to +125°C |
关键差异点
- Lower dropout voltage than non-A version （对比 LD1117DT18TR)
- Same package and pinout as onsemi NCP1117 （对比 NCP1117ST18T3G)
- Lower quiescent current than AP1117 （对比 AP1117-18)
设计说明
Place the input and output capacitors as close to the respective pins as possible. Use a 10µF output capacitor and a 1µF input capacitor, both with low ESR. The thermal pad (TAB) should be connected to a large copper area on the PCB to enhance heat dissipation. For best performance, use a ground plane and keep the trace lengths short.
The LD1117ADT18TR in DPAK package has a junction-to-ambient thermal resistance of 100°C/W. At maximum output current of 800mA and a dropout voltage of 1.1V, the power dissipation is 0.88W, resulting in a temperature rise of 88°C above ambient. Ensure adequate copper area or a heatsink to keep the junction temperature below 125°C.
Do not exceed the maximum input voltage of 15V. Ensure the output capacitor is at least 10µF to maintain stability. Avoid using high-ESR capacitors, as they can cause oscillation. Also, be aware that the dropout voltage increases with temperature, so provide sufficient headroom in high-temperature environments.
合规信息
RoHS compliant per STMicroelectronics. Not AEC-Q100 qualified. Lead-free finish.
