Adafruit INA228 – I2C 85V, 20-bit High or Low Side Power Monitor

The INA228 is a remarkable power monitoring IC, featuring superior support for up to 85VDC common-mode, high or low side measurements and an impressive 20-bit (!) ADC for precise metrics ranging from milliamp to Amp. It also boasts an I2C interface for intuitive configuration of oversampling, alerts, gain settings, and more.

This breakout board offers a comprehensive and precise current sensing solution. It is equipped with the capability to measure both high and low side DC current, the bus voltage, and display calculated power with 1% accuracy. Temperature range, voltage range, and current range are all wide and well beyond the range of two multimeters. Using I2C communication, the data collected is easy to access and understand. This breakout board truly eliminates the need to purchase any other current sensing solutions.

This power monitor is suitable for use in microcontroller, CircuitPython, Arduino, and single-board computer systems. It is compatible with 3V or 5V logic and can accurately measure DC voltages up to 85V. It does not support AC voltages.

Most current-measuring devices operate with some notable constraints that limit what they can be used for. Many are low-side only which can cause issues as the ground reference changes with current. Others like its little sister the INA219B avoid this by measuring on the high side but need to change their shunt resistor to measure different current ranges. The INA228 avoids these limitations, and with the precision 15milliohm shunt resistor on board, it can be used to measure as much as +85V at up to 10A (~10uA per LSB) or 2.75A (~2.5uA per LSB) Continuous on either the high or low side. Wow!

The voltage across the integrated 15 milliohm (.015 ohms!), 0.1% shunt resistor is measured by the internal 20 bit ADC, allowing for measurements over the impressive current range with a resolution of 10uA per LSB in high current measurement mode or 2.5uA per LSB in low current measurement mode.

In a high side configuration the bus voltage measurement and power calculation can be retrieved accurately, however advanced hackers wanting to measure bus voltage in a low side configuration will need to cut the jumper connecting V+ to VBUS and connect the VBUS pin to the voltage bus.

Comes as a fully assembled breakout board with a 3.5mm terminal block and header. Some light soldering is required to attach the header for use in a breadboard. 

Technical Details

Product Dimensions: 25.8mm x 20.2mm x 10.1mm / 1.0″ x 0.8″ x 0.4″

Product Weight: 3.3g / 0.1oz