LD1117DT33TR - 800mA Low Dropout Voltage Regulator | STMicroelectronics
料号： LD1117DT33TR ✓ 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 |
LD1117DT33TR 概述
A low dropout regulator (LDO) is a type of linear voltage regulator that can maintain a stable output voltage even when the input voltage is very close to the output voltage. LDOs are essential in power management systems where noise-sensitive analog circuits require clean, ripple-free power rails. They are part of the voltage regulator family, which also includes switching regulators, and are widely used in consumer electronics, industrial controls, and automotive systems.
Key features of the LD1117DT33TR include a fixed 3.3V output, 800mA output current capability, internal current limiting, and thermal shutdown protection. The device operates over a junction temperature range of -40°C to +125°C, ensuring reliable performance in harsh environments. The SOT-223 package offers a compact footprint with a thermal pad for improved heat dissipation.
The LD1117DT33TR utilizes a PNP pass transistor architecture, which provides low dropout voltage and stable operation. The internal bandgap reference ensures accurate output voltage regulation across temperature and load variations. The device is designed for simplicity, requiring only two external capacitors for stability, making it easy to integrate into various designs.
Typical applications include powering microcontrollers, FPGA core voltages, and analog sensor interfaces. The fixed 3.3V output is ideal for logic circuits and mixed-signal systems. The low dropout voltage allows operation from a 5V rail with sufficient headroom, making it suitable for 5V to 3.3V conversion in embedded systems.
When designing with the LD1117DT33TR, ensure adequate input-to-output voltage headroom to maintain regulation. The input and output capacitors should be placed close to the device pins to minimize parasitic inductance. For high current loads, consider the thermal resistance of the SOT-223 package and provide adequate copper area for heat dissipation.
直接替换替代料： LD1117DT33TR ——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： LD1117DT33TR （相同外形与封装尺寸） ——差异在于 Dropout Voltage, Line Regulation, Load Regulation, Operating Temperature Range, Quiescent Current.
快速对比工具——选择替代料号进行并排对比：
LD1117DT33TR
✅ 直接替换✓ 有现货
$0.15 / 个
查看数据手册 →LD1117S33TR
✅ 直接替换 ⚠️ 规格未核验✓ 有现货
$0.2 / 个
查看数据手册 →LD1117V33
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
AMS1117-3.3
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
NCP1117ST33T3G
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
AP1117-33
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
LD1117DT33TR 最大额定值与电气特性
| 输出类型 | Fixed |
| 输出电压 | 3.3 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 | SOT-223 |
| 安装类型 | Surface Mount |
| Thermal Resistance (θJA) | 50 °C/W (typical) |
| RoHS 状态 | Compliant |
| Output Capacitor | 10 µF (minimum) |
| Input Capacitor | 10 µF (recommended) |
LD1117DT33TR 引脚配置
| 引脚 1 | GND — Ground |
| 引脚 2 | VOUT — Regulated 3.3V output |
| 引脚 3 | VIN — Input voltage |
| 引脚 4 | TAB — Thermal pad, connected to VOUT |
典型应用
LD1117DT33TR 适用于 6 应用s: Microcontroller Power Supply, FPGA Core Voltage, Sensor Interface, Battery-Powered Devices, Industrial Control Systems, Consumer Electronics.
Microcontroller Power Supply
The LD1117DT33TR provides a stable 3.3V rail for microcontrollers, ensuring reliable operation. Its low dropout voltage allows efficient conversion from 5V supplies, and the 800mA current capability supports most MCU boards. The SOT-223 package is compact, making it suitable for space-constrained designs. The device's thermal shutdown protection prevents damage from overcurrent or overtemperature conditions, enhancing system reliability. In a typical application, the regulator is placed between the 5V input and the MCU's VDD pin, with 10µF capacitors on input and output for stability. The low quiescent current of 5mA helps extend battery life in portable devices. Compared to switching regulators, the LDO provides cleaner output with no switching noise, which is critical for analog peripherals. However, power dissipation must be considered; for a 5V to 3.3V conversion at 500mA, the power loss is 0.85W, requiring adequate PCB copper area for heat dissipation.
推荐
FPGA Core Voltage
The LD1117DT33TR can power FPGA core logic that requires a 3.3V supply. Its low dropout voltage ensures stable operation even when the input voltage is close to 3.3V, which is common in battery-powered systems. The 800mA output current is sufficient for small to medium FPGAs. The device's fast transient response helps maintain voltage stability during logic switching. In a typical FPGA application, the regulator is placed close to the FPGA's core power pins, with multiple decoupling capacitors to handle high-frequency current demands. The thermal shutdown feature protects the FPGA from overcurrent events. The SOT-223 package's thermal pad aids in heat dissipation, which is important for continuous operation. Compared to switching regulators, the LDO provides lower noise, which is beneficial for FPGA-based signal processing. However, the power dissipation at higher currents may require additional cooling measures.
推荐
Sensor Interface
The LD1117DT33TR provides a clean 3.3V supply for analog sensors, ensuring accurate readings. Its low noise output minimizes interference in sensitive measurement circuits. The 800mA current capability can power multiple sensors simultaneously. The device's line and load regulation of 0.2% and 0.4% respectively ensure stable voltage under varying conditions. In a typical sensor application, the regulator is used to power a temperature sensor or pressure sensor, with a 10µF output capacitor to filter noise. The low dropout voltage allows operation from a 3.6V battery, extending battery life. The thermal shutdown protection prevents damage from short circuits. Compared to switching regulators, the LDO's low noise is essential for high-precision analog measurements. However, the power dissipation must be managed, especially when powering multiple sensors at higher currents.
推荐
Battery-Powered Devices
The LD1117DT33TR is ideal for battery-powered devices due to its low quiescent current of 5mA and low dropout voltage. It can efficiently regulate a 3.3V output from a 3.7V Li-ion battery, maximizing battery life. The 800mA output current supports a wide range of portable applications. The device's thermal shutdown protection ensures safe operation during high current draws. In a typical battery-powered device, the regulator is placed between the battery and the main circuit, with a 10µF input capacitor to handle battery voltage fluctuations. The low dropout voltage allows the device to operate until the battery is nearly discharged. Compared to switching regulators, the LDO's simplicity and low noise are advantageous for audio and RF circuits. However, the power dissipation in the LDO can reduce efficiency, so it is important to match the load current to the regulator's capabilities.
推荐
Industrial Control Systems
The LD1117DT33TR is suitable for industrial control systems that require a reliable 3.3V supply. Its wide operating temperature range of -40°C to +125°C ensures performance in harsh environments. The 800mA output current can power logic circuits, relays, and sensors. The device's thermal shutdown and current limiting features protect against faults. In a typical industrial application, the regulator is used to power a PLC's I/O modules, with input and output capacitors for stability. The low dropout voltage allows operation from a 5V rail with sufficient headroom. The SOT-223 package is robust and suitable for PCB mounting in industrial equipment. Compared to switching regulators, the LDO's low noise is beneficial for analog control signals. However, the power dissipation at high currents may require heatsinking or forced air cooling.
推荐
Consumer Electronics
The LD1117DT33TR is widely used in consumer electronics such as set-top boxes, routers, and gaming consoles. Its fixed 3.3V output is compatible with many digital ICs. The 800mA current capability supports multiple peripherals. The device's low cost and small SOT-223 package make it ideal for high-volume production. In a typical consumer device, the regulator is used to power a system-on-chip (SoC) or memory, with 10µF capacitors for stability. The low dropout voltage allows efficient conversion from a 5V USB supply. The thermal shutdown protection prevents damage from overheating. Compared to switching regulators, the LDO's simplicity reduces BOM cost and design complexity. However, the power dissipation must be considered for continuous operation, and adequate PCB copper area is recommended.
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推荐产品汇总
工程参考数据： LD1117DT33TR ——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 | AMS1117-3.3 | NCP1117ST33T3G |
|---|---|---|---|---|
| Package | SOT-223 | SOT-223 | SOT-223 | SOT-223 |
| Brand | STMicroelectronics | STMicroelectronics | Advanced Monolithic Systems | onsemi |
| Output Voltage | 3.3V | 3.3V | 3.3V | 3.3V |
| Maximum Output Current | 800mA | 800mA | 1A | 1A |
| Dropout Voltage | 1.1V at 800mA | 1.1V at 800mA | 1.3V at 1A | 1.2V at 1A |
| 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 |
| RoHS Compliant | Yes | Yes | Yes | Yes |
关键差异点
- Low dropout voltage of 1.1V at 800mA （对比 AMS1117-3.3)
- Lower quiescent current of 5mA （对比 NCP1117ST33T3G)
- Wide operating temperature range （对比 AP1117-33)
设计说明
The SOT-223 package has a thermal resistance (θJA) of approximately 50°C/W. For a 5V to 3.3V conversion at 800mA, power dissipation is 1.36W, resulting in a junction temperature rise of 68°C above ambient. Ensure adequate PCB copper area (at least 1 square inch) connected to the thermal pad to keep the junction temperature within the -40°C to +125°C range.
Place a 10µF input capacitor and a 10µF output capacitor as close to the VIN and VOUT pins as possible. Use low-ESR ceramic capacitors for better high-frequency performance. The thermal pad (pin 4) should be connected to a large copper area for heat dissipation and also connected to VOUT for proper operation.
Do not exceed the maximum input voltage of 15V. Ensure the output capacitor is at least 10µF to maintain stability; using a smaller capacitor may cause oscillation. The device does not have an enable pin, so power sequencing must be handled externally if required.
合规信息
RoHS compliant per STMicroelectronics product page. AEC-Q100 qualification not specified for this part.
