AMS1117 1.2V 1A LDO Voltage Regulator SOT-223

AMS1117-1.2 1.2V 1A LDO Voltage Regulator (SOT-223) delivers a compact, reliable low-dropout regulation solution for embedded boards and power modules. Designers use it to provide a stable 1.2 V rail for processors, sensors, and analog blocks where board space is limited and up to 1 A output is required.

Key Features:

• Fixed 1.2 V Output: Provides a steady 1.2 V rail for low-voltage digital and analog circuits.
• Up to 1 A Output Current: Supports moderate current loads in compact designs.
• Low Dropout: Maintains regulation with a small VIN − VOUT differential for battery-powered systems.
• SOT-223 Package: Through-hole / PCB-mount friendly package with a thermal tab for heatsinking.
• Simple External Components: Requires only input and output decoupling capacitors for stable operation.
• Short-Circuit and Thermal Protection: Integrates protection to prevent catastrophic failure under fault conditions.

Technical Specifications:

• Output Voltage: 1.20 V (fixed)
• Maximum Output Current: 1.0 A (see thermal limits and PCB layout)
• Input Voltage Range: Typically up to 15 V absolute maximum; maintain VIN ≥ VOUT + dropout margin
• Dropout Voltage: Typ ~1.0 V at 1 A (varies by manufacturer and temperature)
• Quiescent Current (I_Q): Typ ~5–10 mA (no-load supply current)
• Line Regulation: Low; consult datasheet for exact mV/V figures
• Load Regulation: Low; depends on PCB thermal path and output capacitor ESR
• Thermal Shutdown: Built-in to protect against over-temperature conditions
• Short-Circuit Protection: Current limiting provided
• Output Tolerance: Manufacturer-dependent. Verify in supplier datasheet for guaranteed tolerance and temperature behavior.
• Recommended Output Capacitor: Low-ESR electrolytic or solid polymer (e.g., 10 µF with specified ESR). Follow datasheet recommendations for stability.

Mechanical Specifications:

• Package: SOT-223 (four-lead appearance; tab connected to GND or as specified by vendor)
• Mounting: PCB surface-mount with thermal via and copper area for heat dissipation
• Lead Finish: Tin or matte tin plating for reliable solderability
• Body Material: Molded epoxy suitable for commercial temperature ranges

Dimensions:

• SOT-223 Typical Body: ~6.5 mm × ~6.5 mm (body footprint varies; confirm with mechanical drawing)
• Tab and Overall Height: Tab extends for PCB mounting and heatsinking; check vendor mechanical datasheet for exact millimetres.

Pinout and Wiring:

• Pin 1 (Left): Adjust/Ground/NC depending on variant. For fixed AMS1117-1.2, follow supplier pin mapping (often GND on tab and specific pin mapping on body).
• Pin 2 (Middle): Output (1.2 V)
• Pin 3 (Right): Input (VIN)
• Tab: Connect to ground plane or heatsink per manufacturer drawing; verify whether tab is tied to GND.
• Wiring Notes: Place input capacitor close to VIN pin. Place recommended low-ESR output capacitor close to VOUT pin to ensure regulator stability. Use wide copper and thermal vias for currents near 1 A.

Datasheet Reference:

• Download the official AMS1117-1.2 datasheet from the supplier or major distributors for guaranteed electrical characteristics, thermal curves, recommended PCB layout, and capacitor ESR guidelines.

Applications:

• Embedded Microcontrollers: Provide a stable 1.2 V rail for low-voltage cores and SoCs.
• Sensor and Analog Front-Ends: Use for precision reference rails when low noise and stable regulation are required.
• Battery-Powered Devices: Regulate down from higher cell voltages while conserving board area.
• Power Modules and Prototyping: Integrate into breakout boards and reference supplies for test benches.

Equivalent Models:

• LM1117-1.2: Common drop-in alternative with similar electrical behavior; verify pinout and thermal limits.
• LD1117-1.2: Vendor variants that follow the same LDO family form factor and ratings.
• Other LDOs: Choose LDOs with comparable dropout, quiescent current, and 1.2 V fixed output when substituting. Always validate stability with the chosen output capacitor.

Package Includes:

• 1 x AMS1117-1.2 1.2V 1A LDO Voltage Regulator (SOT-223)