STEMMA QT ADS122C04 24-Bit ADC - Adafruit 6432

Description

Adafruit ADS122C04 is a precision 24-bit analog-to-digital converter (ADC) module designed for accurate measurement of analog signals in electronic, scientific, and measurement applications. The device supports data acquisition at rates of up to 2000 samples per second (2 kSPS), which distinguishes it from many other high-resolution ADCs. With support for four input channels, the module can operate either as four single-ended inputs or as two differential inputs, allowing flexible configuration depending on the type of sensors or analog circuitry used.

The module is based on the Texas Instruments ADS122C04 converter, which features programmable gain from 1 to 128. This allows precise amplification of very small signals such as those generated by bridge sensors, thermocouples, or other precision measurement systems. The chip also integrates programmable current sources, which can be used to excite sensors or implement specialized measurement configurations. A built-in 2.048 V reference voltage ensures stable measurements, while additional pins allow the use of an external reference if required.

The module also includes an integrated temperature sensor, enabling monitoring of device temperature and compensation of temperature effects on measurements. A digital filter with simultaneous 50 Hz and 60 Hz noise rejection ensures stable results even in electrically noisy environments. The device also provides a reset input and an accurate internal oscillator, simplifying integration into measurement systems.

Communication with a microcontroller is handled via the I2C interface, allowing easy connection to platforms such as Arduino, Raspberry Pi, ARM microcontrollers, and other single-board computers. The chip supports several I2C speed modes including Fast-Mode Plus, enabling maximum sampling performance. Additional address pins allow up to four ADC devices to be connected on a single I2C bus.

The board is designed in the STEMMA QT standard, enabling quick connection using QT or Qwiic cables. Connectors on both sides of the board allow multiple modules to be chained on the same bus. The module operates with a supply voltage from 2.3 V to 5.5 V, ensuring compatibility with both 3.3 V and 5 V systems. Thanks to its compact size, high accuracy, and extensive configuration options, the Adafruit ADS122C04 is well suited for data acquisition systems, laboratory instruments, automation systems, IoT devices, and advanced measurement projects requiring high resolution.

Features

• Chip: ADS122C04
• Type: 24-bit analog-to-digital converter (ADC)
• Number of channels: 4 single-ended inputs or 2 differential inputs
• Maximum sampling rate: up to 2 kSPS
• Effective resolution: up to 20 bits
• Programmable gain amplifier (PGA): 1 to 128
• Communication interface: I2C
• Supported I2C speed modes: Standard-Mode, Fast-Mode, Fast-Mode Plus
• Built-in reference voltage: 2.048 V
• Reference voltage drift: 5 ppm/°C (typical)
• Integrated current sources: programmable from 10 µA to 1.5 mA
• Built-in oscillator with 2% accuracy
• Integrated temperature sensor with typical accuracy of 0.5°C
• Digital filter with simultaneous 50 Hz and 60 Hz rejection at 20 SPS
• Reset input
• Up to 4 devices supported on a single I2C bus
• STEMMA QT / Qwiic connectors
• Supply voltage: 2.3 V to 5.5 V
• Current consumption: 315 µA
• PCB mounting holes
• Dimensions: 25.5 × 17.7 × 4.7 mm
• Weight: 1.6 g

Kit contains

• Adafruit ADS122C04 24-Bit ADC STEMMA QT/Qwiic module
• 2.54 mm gold pin header