LD1117ADT33TR - 3.3V Fixed 800mA LDO Regulator | STMicroelectronics
MPN: LD1117ADT33TR ✓ NakahandaLD1117ADT33TR Ulas
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 use a pass transistor operating in the saturation region, allowing a low dropout voltage. In the system hierarchy, an LDO is a linear regulator, which is a type of voltage regulator, which falls under power management ICs, which are semiconductors. This hierarchy is essential for understanding where the LD1117ADT33TR fits in power management design.
Key features of the LD1117ADT33TR include a dropout voltage of typically 1.1V at 800mA load, a quiescent current of 5mA, and a line regulation of 0.2% (typical). It also offers thermal shutdown and internal current limiting, providing robust protection for the load. The fixed 3.3V output eliminates the need for external resistor dividers, simplifying design and reducing component count.
The LD1117ADT33TR is built on a bipolar process, offering low noise and fast transient response. The DPAK package provides a thermal resistance of 50°C/W (junction-to-ambient), allowing moderate power dissipation without a heatsink. The device is RoHS compliant and lead-free, meeting modern environmental standards.
Typical applications include powering microcontrollers, FPGAs, and digital logic in embedded systems, as well as providing a clean 3.3V rail for sensors and interface circuits. It is also used in set-top boxes, routers, and other consumer electronics where a stable 3.3V supply is required.
When designing with the LD1117ADT33TR, ensure adequate input-output voltage headroom to maintain regulation. A minimum input voltage of 4.75V is required for 3.3V output. Use a 10µF output capacitor for stability, and place it close to the output pin. The thermal pad should be connected to a large copper area for heat dissipation.
Mga alternatibo na pwedeng ilagay na LD1117ADT33TR — parehas na package, pin-to-pin na katugmang. Hindi kasama ang mga bahagi ng iba't-ibang package na nangangailangan ng pagpapaayos ng PCB.
LD1117ADT33TR
✅ Drop-InMagkontak para sa presyo
Tingnan ang Datasheet →AMS1117-3.3
✅ Drop-In ⚠️ Mga Talaan Hindi Naiwerikmo📋 Alternatibo na Reference (hindi sa katalogo)
AP1117-33
✅ Drop-In ⚠️ Mga Talaan Hindi Naiwerikmo📋 Alternatibo na Reference (hindi sa katalogo)
LD1117ADT33TR Mga Pinakamataas na Rating at Electrical Characteristics
| Type ng Output | Fixed |
| Output Volte | 3.3 V |
| Maksimum na Current ng Output | 800 mA |
| Hanay ng Voltage ng Input | 4.75 V to 15 V |
| Voltage ng Dropout | 1.1 V (typical at 800 mA) |
| Kuru-kuryente ng Kapayapaan | 5 mA |
| Line Regulation | 0.2% (typical) |
| Load Regulation | 0.4% (typical) |
| Thermal Resistance, Junction-to-Ambient | 50 °C/W |
| Hanay ng Temperature na Operasyon | -40°C to +125°C |
| Packhaging | DPAK (TO-252) |
| Uri ng Pagpapasok | Surface Mount |
| Level ng MSL | 1 (unlimited) |
| Tindminan RoHS | Compliant |
| Lead-Free | Yes |
Pin Configuration ng LD1117ADT33TR
| Pin 1 | GND — Ground |
| Pin 2 | VOUT — Regulated 3.3V output |
| Pin 3 | VIN — Input voltage (4.75V to 15V) |
| Pin Tab | VOUT — Exposed pad connected to VOUT |
Tipikal na mga Gamit
LD1117ADT33TR ay nararapat para sa 6 aplikasyons: Microcontroller Power Supply, FPGA Core Voltage, Sensor Interface, Set-Top Box, Router and Networking Equipment, Industrial Control.
Microcontroller Power Supply
The LD1117ADT33TR provides a stable 3.3V rail for microcontrollers, ensuring reliable operation. Its 800mA output current is sufficient for most MCUs and peripheral circuits. The low dropout voltage allows operation from 5V rails with minimal power loss. The fixed output simplifies design, and the thermal shutdown protects the MCU from overheating. In a typical application, the LDO is placed between the 5V supply and the MCU's VDD pin, with a 10µF capacitor on the output for stability. The low quiescent current of 5mA is acceptable for non-battery-powered systems. Compared to switching regulators, the LDO provides a cleaner output with no switching noise, which is critical for analog peripherals. However, power dissipation is higher; for a 5V-to-3.3V conversion at 500mA, power dissipation is 0.85W, requiring adequate PCB copper for heat sinking.
Inirekomenda
FPGA Core Voltage
The LD1117ADT33TR can power the core logic of small FPGAs that require 3.3V. Its 800mA output current is suitable for low-power FPGAs like the ICE40 series. The low dropout voltage ensures regulation even with a 5V input. The thermal shutdown protects the FPGA from thermal damage. In a typical design, the LDO is placed close to the FPGA's VCCINT pins, with multiple decoupling capacitors. The fixed 3.3V output eliminates the need for external resistors. The LDO's fast transient response helps maintain stable voltage during FPGA switching activity. However, for larger FPGAs with higher current demands, a switching regulator may be more efficient. The LD1117ADT33TR is best for small, low-power FPGAs in cost-sensitive applications.
Inirekomenda
Sensor Interface
The LD1117ADT33TR provides a clean 3.3V supply for sensors and analog front-ends. Its low noise and stable output are essential for accurate sensor readings. The 800mA output current can power multiple sensors. The thermal shutdown protects the sensors from over-temperature. In a typical application, the LDO is used to power a temperature sensor and an ADC, with a 10µF capacitor on the output. The fixed 3.3V output simplifies the design. The LDO's line regulation of 0.2% ensures stable output even with input voltage variations. Compared to switching regulators, the LDO eliminates switching noise that could corrupt sensor measurements. However, the LDO's quiescent current of 5mA may be a concern for battery-powered sensor nodes, where a low-quiescent LDO would be preferred.
Inirekomenda
Set-Top Box
The LD1117ADT33TR is used in set-top boxes to provide a stable 3.3V rail for the main processor and tuner. Its 800mA output current is sufficient for these components. The low dropout voltage allows operation from a 5V rail. The thermal shutdown protects the device in case of overload. In a typical set-top box, the LDO is placed on the main board, with a heat sink or copper area for dissipation. The fixed 3.3V output simplifies the power supply design. The LDO's low noise is important for the tuner's RF performance. Compared to switching regulators, the LDO provides a cleaner output, but at the cost of efficiency. For a 12V-to-3.3V conversion at 500mA, power dissipation is 4.35W, requiring a heatsink. The LD1117ADT33TR is a cost-effective solution for set-top boxes.
Inirekomenda
Router and Networking Equipment
The LD1117ADT33TR provides a stable 3.3V supply for networking processors and PHY chips. Its 800mA output current is adequate for these components. The low dropout voltage allows operation from a 5V rail. The thermal shutdown protects the equipment from overheating. In a typical router, the LDO is used to power the main SoC and Ethernet PHY, with a 10µF capacitor on the output. The fixed 3.3V output simplifies the design. The LDO's low noise is important for the PHY's signal integrity. Compared to switching regulators, the LDO provides a cleaner output, but with lower efficiency. For a 5V-to-3.3V conversion at 500mA, power dissipation is 0.85W, which is manageable with proper PCB layout. The LD1117ADT33TR is a reliable choice for networking equipment.
Inirekomenda
Industrial Control
The LD1117ADT33TR is used in industrial control systems to provide a stable 3.3V supply for PLCs and sensors. Its 800mA output current is sufficient for these applications. The wide input voltage range (up to 15V) allows operation from 24V industrial rails with a pre-regulator. The thermal shutdown protects the device in harsh environments. In a typical industrial application, the LDO is used to power a microcontroller and fieldbus interface, with a 10µF capacitor on the output. The fixed 3.3V output simplifies the design. The LDO's operating temperature range of -40°C to +125°C makes it suitable for industrial environments. Compared to switching regulators, the LDO provides a cleaner output, but with higher power dissipation. For a 24V-to-3.3V conversion at 500mA, power dissipation is 10.35W, requiring a heatsink or a pre-regulator. The LD1117ADT33TR is a robust choice for industrial control.
Inirekomenda
Buod ng mga Inirekomendang Produkto
Impormasyon ng Talumpati sa Engineering for LD1117ADT33TR — ikabit, gabay sa disenyo, at impormasyon ng pagsunod sa kautusan.
Paunawang Hanapin
Ikabit sa Mga Alternatibo
| Parametro | Ito ang Producto | LD1117DT33TR | AMS1117-3.3 | NCP1117ST33T3G | AP1117-33 |
|---|---|---|---|---|---|
| Package | DPAK (TO-252) | SOT-223 | DPAK (TO-252) | SOT-223 | DPAK (TO-252) |
| Brand | STMicroelectronics | STMicroelectronics | Advanced Monolithic Systems | onsemi | Diodes Incorporated |
| Output Voltage | 3.3V | 3.3V | 3.3V | 3.3V | 3.3V |
| Maximum Output Current | 800mA | 800mA | 1A | 1A | 1A |
| Input Voltage Range | 4.75V to 15V | 4.75V to 15V | 4.75V to 12V | 4.75V to 18V | 4.75V to 18V |
| Dropout Voltage | 1.1V typical | 1.1V typical | 1.1V typical | 1.1V typical | 1.1V typical |
| Quiescent Current | 5mA | 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 | -40°C to +125°C |
Pangunahing mga Pagkakaiba
- Wide input voltage range up to 15V (kumpara saAMS1117-3.3)
- Lower quiescent current than some alternatives (kumpara saNCP1117ST33T3G)
- Proven STMicroelectronics quality (kumpara saAP1117-33)
Talaan ng Disenyo
The LD1117ADT33TR has a junction-to-ambient thermal resistance of 50°C/W. At 5V input and 3.3V output with 800mA load, power dissipation is (5-3.3)*0.8 = 1.36W, causing a temperature rise of 68°C. Ensure adequate PCB copper area (at least 1 square inch) connected to the thermal pad to keep junction temperature below 125°C. For higher input voltages, consider a heatsink or a pre-regulator.
Place a 10µF ceramic capacitor on the output and a 10µF capacitor on the input, as close to the pins as possible. The output capacitor is required for stability. Use a 0.1µF capacitor in parallel for high-frequency decoupling. The thermal pad should be soldered to a large copper area for heat dissipation.
Do not exceed the maximum input voltage of 15V. Ensure the input voltage is at least 4.75V to maintain regulation. The LD1117ADT33TR is a fixed output device; do not attempt to adjust the output voltage. Use a proper heat sink for high power dissipation. Avoid reverse polarity on the input.
Impormasyon ng Pagsunod sa Kautusan
RoHS compliant and lead-free per STMicroelectronics datasheet. Not AEC-Q100 qualified. Halogen-free status not specified in the provided data.
