INA226 High/Low-Side Current, Voltage & Power Monitor Module

Precision I2C current, voltage, and power monitoring module using the INA226 sensor. Measures bus voltages from 0-36V and calculates current and power via shunt resistor. Features 0.1% gain accuracy, programmable averaging, and 16 configurable I2C addresses for multi-sensor setups. Ideal for battery monitoring, power supply analysis, solar systems, and precision current measurement in embedded applications.

Technical Specifications:

• IC: Texas Instruments INA226
• Interface: I2C / SMBus compatible
• Bus Voltage Range: 0V - 36V (high-side or low-side sensing)
• Supply Voltage: 2.7V - 5.5V
• Supply Current: 330µA (typical)
• Measurement Accuracy: 0.1% gain error (max), 10µV offset (max)
• ADC Resolution: 16-bit
• Shunt Voltage Range: ±81.92mV (typical configuration)
• Current Range: Determined by shunt resistor value
• I2C Address: 16 programmable addresses (0x40-0x4F via A0/A1 pins)
• I2C Clock Speed: Up to 400kHz (fast mode)
• Conversion Time: Programmable (140µs - 8.244ms)
• Averaging: Configurable (1 to 1024 samples)
• Operating Temperature: -40°C to +125°C
• Package: 10-pin VSSOP on breakout board

Pin Configuration:

• VCC: Power supply (2.7V - 5.5V)
• GND: Ground
• SDA: I2C data line
• SCL: I2C clock line
• VBUS: Bus voltage measurement input (0-36V)
• IN+: Non-inverting current sense input
• IN-: Inverting current sense input
• ALERT: Programmable alert/alarm output
• A0/A1: I2C address selection pins

Measured Parameters:

• Bus Voltage: Direct voltage measurement (0-36V)
• Shunt Voltage: Voltage drop across shunt resistor
• Current: Calculated from shunt voltage and resistance
• Power: Calculated from current × voltage

Features:

• Simultaneous current, voltage, and power measurement
• High-side or low-side current sensing
• High precision (0.1% accuracy)
• Programmable conversion time and averaging
• Internal calculation of current and power (no external math needed)
• Multiple alert functions (over/under voltage, current, power)
• 16 I2C addresses allow multiple sensors on one bus
• Wide common-mode voltage range (0-36V)
• Low quiescent current (330µA)

Applications:

• Battery management and monitoring
• Solar panel power monitoring (MPPT systems)
• Server and computing power analysis
• Telecom equipment monitoring
• DC power supply efficiency testing
• Battery charger current monitoring
• Motor current measurement
• Energy consumption tracking
• Test and measurement equipment
• Industrial power management

Typical Wiring:

• Connect shunt resistor in series with load
• IN+ to high side of shunt, IN- to low side
• VBUS to positive bus voltage being monitored
• VCC/GND to microcontroller 3.3V or 5V
• SDA/SCL to microcontroller I2C pins

Shunt Resistor Selection:

• Lower resistance = higher current capacity, lower accuracy
• Higher resistance = lower current capacity, higher accuracy
• Common values: 0.01Ω (10A max), 0.1Ω (1A max)
• Maximum shunt voltage: ±81.92mV

Programmable Features:

• Conversion time per channel (140µs to 8.244ms)
• Averaging mode (1 to 1024 samples for noise reduction)
• Alert threshold for voltage, current, power limits
• Operating mode (continuous, triggered, power-down)

Alert Function:

• Programmable over/under voltage alerts
• Programmable over/under current alerts
• Programmable over/under power alerts
• Conversion ready flag

Compatible with Arduino, ESP32, Raspberry Pi, STM32, and any microcontroller with I2C support. Libraries available for easy current/voltage/power readout.