AMS1117 1.5V Low Dropout Voltage Regulator SOT-223

AMS1117 1.5V Low Dropout Voltage Regulator SOT-223 is a high-efficiency, fixed-output linear regulator designed to provide a stable 1.5V supply for modern low-voltage digital circuits. This device excels at maintaining a precise output voltage even when the input voltage remains only slightly higher than the desired output level. Consequently, it serves as an ideal solution for battery-powered devices and high-efficiency power management systems where minimizing heat and voltage overhead is critical. The SOT-223 package offers an excellent balance between a compact footprint and effective thermal dissipation. Furthermore, the internal circuitry provides comprehensive protection against over-current and over-temperature conditions, ensuring long-term reliability in demanding environments. Therefore, engineers frequently select the AMS1117-1.5 to power sensitive logic components, low-voltage microcontrollers, and memory modules.

Key Features:

• Low Dropout Performance: The regulator operates with a very low dropout voltage, typically around 1.1V at full load, maximizing power efficiency.
• Fixed 1.5V Output: It provides a consistent 1.5V DC output, which eliminates the need for external voltage-setting resistors and simplifies PCB design.
• Thermal Overload Protection: Built-in thermal shutdown circuitry prevents the device from failing due to excessive heat during high-load conditions.
• Current Limiting: Internal current limiting protects the regulator and the connected load from damage caused by short circuits or over-current surges.
• Compact SOT-223 Package: The surface-mount design allows for automated assembly while the large tab ensures efficient heat transfer to the copper plane.

Technical Specifications:

• Output Voltage: 1.5 V (±1.5% accuracy)
• Maximum Output Current: 800 mA to 1 A (Depending on thermal conditions)
• Maximum Input Voltage: 15 V (Absolute Maximum)
• Dropout Voltage: ≈ 1.1 V (at 800 mA load)
• Quiescent Current: ≈ 5 mA (Typically)
• Line Regulation: 0.2% (Maximum)
• Load Regulation: 0.4% (Maximum)
• Operating Junction Temperature: −40°C to +125°C

Mechanical Specifications:

• Package Type: SOT-223 (Surface Mount)
• Lead Finish: Lead-Free (RoHS Compliant)
• Case Material: Molded Plastic (UL 94 V-0 Flammability Rated)
• Moisture Sensitivity: MSL Level 1

Dimensions:

• Body Length: ≈ 6.5 mm
• Body Width: ≈ 3.5 mm
• Total Width (including pins): ≈ 7.0 mm
• Total Height: ≈ 1.8 mm
• Pin Pitch: 2.3 mm

Pinout and Wiring:

• Pin 1 (GND/ADJ): Connect this pin directly to the system ground (0V) for the fixed 1.5V version.
• Pin 2 (Vout/TAB): This is the regulated 1.5V output; however, note that the large center tab is also electrically connected to this pin.
• Pin 3 (Vin): Connect the unregulated input voltage (minimum 2.6V to 3V recommended for stable operation) to this pin.
• Wiring Note: You must place a 10μF tantalum or electrolytic capacitor on both the input and output pins to ensure stability and reduce ripple.

Datasheet Reference:

• Download AMS1117 Series Datasheet

Commonly Used in:

• Digital Logic Rails: Providing the specific 1.5V core voltage required by many FPGAs and CPLDs.
• Memory Modules: Powering low-voltage DDR memory components in embedded computing boards.
• Microcontroller Boards: Supplying secondary power rails for peripherals that operate at lower voltages than the main system bus.

Applications:

• Battery Management: Efficiently stepping down battery voltage to 1.5V for portable electronics.
• Communication Equipment: Regulating power for signal processing ICs in networking hardware.
• Consumer Electronics: Standard power regulation in set-top boxes, DVD players, and handheld gadgets.

Equivalent Models:

• LM1117-1.5: A widely available alternative from Texas Instruments that offers identical pinout and performance characteristics.
• LD1117V15: The STMicroelectronics version of the 1.5V fixed regulator, however, verify the package type as it also comes in TO-220.
• NCP1117ST15T3G: ON Semiconductor’s high-quality equivalent in the SOT-223 package.

Package Includes:

• 1 x AMS1117 1.5V Low Dropout Voltage Regulator SOT-223