LD1117DT33TR - 800mA Low Dropout Voltage Regulator | STMicroelectronics
MPN: LD1117DT33TR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 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 |
Drop-in alternatives for LD1117DT33TR — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
LD1117DT33TR
✅ Drop-In✓ 99,999 In Stock
$0.15 / Unit
View Datasheet →LD1117S33TR
✅ Drop-In✓ 99,999 In Stock
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View Datasheet →LD1117V33
✅ Drop-In📋 Reference alternative (not in catalog)
AMS1117-3.3
✅ Drop-In📋 Reference alternative (not in catalog)
NCP1117ST33T3G
✅ Drop-In📋 Reference alternative (not in catalog)
AP1117-33
✅ Drop-In📋 Reference alternative (not in catalog)
LD1117DT33TR Maximum Ratings & Electrical Characteristics
| Output Type | Fixed |
| Output Voltage | 3.3 V |
| Maximum Output Current | 800 mA |
| Input Voltage Range | Up to 15 V |
| Dropout Voltage | 1.1 V at 800 mA |
| Line Regulation | 0.2 % (typical) |
| Load Regulation | 0.4 % (typical) |
| Quiescent Current | 5 mA (typical) |
| Operating Temperature Range | -40°C to +125°C |
| Package | SOT-223 |
| Mounting Type | Surface Mount |
| Thermal Resistance (θJA) | 50 °C/W (typical) |
| RoHS Status | Compliant |
| Output Capacitor | 10 µF (minimum) |
| Input Capacitor | 10 µF (recommended) |
LD1117DT33TR Pin Configuration
| Pin 1 | GND — Ground |
| Pin 2 | VOUT — Regulated 3.3V output |
| Pin 3 | VIN — Input voltage |
| Pin 4 | TAB — Thermal pad, connected to VOUT |
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
LD1117DT33TR is suitable for 6 applications: 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.
Recommended
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.
Recommended
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.
Recommended
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.
Recommended
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.
Recommended
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.
Recommended
Recommended Products Summary
Engineering reference data for LD1117DT33TR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | 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 |
Key Differentiators
- Low dropout voltage of 1.1V at 800mA (vs AMS1117-3.3)
- Lower quiescent current of 5mA (vs NCP1117ST33T3G)
- Wide operating temperature range (vs AP1117-33)
Design Notes
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.
Compliance Information
RoHS compliant per STMicroelectronics product page. AEC-Q100 qualification not specified for this part.
