AMS1117 3.3V DC-DC Step-Down Linear Power Supply Module

AMS1117 3.3V DC-DC Step-Down Linear Power Supply Module is a compact low-dropout (LDO) linear voltage regulator breakout board based on the Advanced Monolithic Systems AMS1117-3.3 IC. Designed to step down a 4.5V to 12V DC input (most commonly a 5V Arduino or USB rail) into a clean, ripple-free 3.3V DC output at up to 800mA, it features onboard input/output tantalum decoupling capacitors, a power status LED, and breadboard-ready 2.54mm pin headers for powering 3.3V Wi-Fi, RF, and sensor modules.

Key Features:

• Clean Ripple-Free 3.3V LDO Output: Linear regulation eliminates high-frequency switching noise, making it ideal for noise-sensitive RF transceivers (nRF24L01+, LoRa, ESP8266) and analog ADCs.
• Low 1.1V Dropout Voltage: Regulates a rock-solid 3.3V ± 1% output from inputs as low as 4.5V–4.75V DC (such as a standard 5V USB rail) up to 12V DC.
• Up to 800mA Output Current: Supplies ample 3.3V current for ESP8266/ESP-01 Wi-Fi transmission bursts that exceed the tiny 50mA 3.3V pin of an Arduino UNO.
• Onboard Decoupling & Status LED: Includes SMD tantalum/ceramic filter capacitors and a bright red power indicator LED.
• 3-Pin 2.54mm Header Layout: Standard 0.1-inch pitch pins (VIN, GND, VOUT) plug directly into solderless breadboards or female jumper wires.

Technical Specifications:

• Regulator IC: AMS1117-3.3 Low-Dropout Linear Regulator (SOT-223)
• Input Voltage Range: 4.5V to 12.0V DC (5.0V Nominal Recommended for Low Heat)
• Output Voltage: 3.3V DC ± 1% Fixed
• Maximum Output Current: 800 mA Continuous (1.0A Peak)
• Dropout Voltage: ~1.1V to 1.2V at 800mA
• Built-In Protection: Thermal Overload Shutdown & Short-Circuit Current Limiting
• Operating Temperature Range: -40°C to +125°C (Junction)

Mechanical Specifications:

• PCB Material: FR-4 Double-Sided Blue Fiberglass Board
• Pin Interface: 3-Pin or Dual-Row 2.54mm Pitch Header (VIN, OUT, GND)

Dimensions:

• Length: 25 mm
• Width: 11 mm
• Height: 7 mm
• Weight: ~2 g

Pinout and Wiring:

• VIN (IN): Connect 4.5V to 12V DC input (5V DC recommended to minimize linear thermal dissipation $P = (V_{IN} – 3.3V) times I_{LOAD}$).
• OUT (VOUT): Regulated +3.3V DC output.
• GND: Common ground shared between input and output.

Datasheet Reference:

• Primary IC Datasheet: Advanced Monolithic Systems AMS1117 1A Low-Dropout Voltage Regulator Datasheet (PDF)

Commonly Used in:

• ESP8266 ESP-01 & nRF24L01+ 3.3V RF Transceiver Power Rails
• 5V Arduino UNO / Mega to 3.3V Sensor Power Supplies
• STM32, RP2040, and 3.3V I2C/SPI Sensor Breadboarding
• Low-Noise Analog Audio and Precision ADC Reference Rails

Applications:

• Steps down a 5V Arduino or USB supply to a clean 3.3V 800mA rail to prevent brownout resets on ESP8266 ESP-01 and nRF24L01+ wireless modules.
• Powers 3.3V-only I2C/SPI sensors (BMP280, MPU6050, SD card modules, TOF laser sensors) safely on 5V development boards.
• Provides a zero-switching-ripple 3.3V supply for sensitive analog instrumentation amplifiers and microphone preamps.

Equivalent Models:

• AMS1117 5V and 3.3V Dual Linear Step-Down Power Supply Module: Dual-stage board providing both 5V and 3.3V outputs from a 6V–12V input.
• MINI560 DC 3.3V 5A Step-Down Stabilized Buck Converter Module: High-efficiency switching 3.3V 5A buck converter for high-current loads.

Package Includes:

• 1 × AMS1117 3.3V DC-DC Step-Down Linear Power Supply Module