Adafruit MCP3421 18-Bit ADC - STEMMA QT / Qwiic

The Adafruit MCP3421 18-Bit ADC is a simple, inexpensive, and easy to use 18-bit, 240 SPS, single-channel ADC with an I2C interface capable of up to 3.4MHz clock rate. It features differential inputs, adjustable gain, and a built-in precision/low-drift reference voltage, making it ideal for reading sensors like strain gauges, pressure sensors, or thermocouples.

The ADC supports multiple bit resolutions: 12-bit at 240 SPS for faster sampling, and 18-bit at 3.5 SPS for high precision. The differential input allows measuring positive or negative differences between two signals, each ranging from 0 to 2.048V.

Designed on a custom PCB with the STEMMA QT form factor, it easily interfaces with compatible development boards and sensors via solderless STEMMA QT or SparkFun Qwiic connectors.

• 18-bit delta-sigma ADC with differential input operation
• On-board voltage reference with 2.048V ± 0.05% accuracy and 15 ppm/°C drift
• Programmable gain amplifier with gains of 1, 2, 4, or 8
• Multiple data rates: 3.75 SPS (18-bit), 15 SPS (16-bit), 60 SPS (14-bit), 240 SPS (12-bit)
• One-shot or continuous conversion modes
• Includes 0.1" standard header pins and four mounting holes

Note: STEMMA QT cables are not included but available separately.

Dimensions: 25.4mm x 17.8mm x 12.3mm (1.0" x 0.7" x 0.5")
Weight: 3.0g