SparkFun Current Sensor – INA237 (Qwiic)

Resources:

Schematic
KiCad Files
Board Dimensions
Hookup Guide
Datasheet (INA237)
SparkFun INA2XX Arduino Library
GitHub Repository

16-Bit INA237 Qwiic Current and Power Sensor with 15 mOhm Shunt and Programmable Alerts
The SparkFun INA237 Qwiic Current Sensor is a precision DC and power-monitoring breakout based on the Texas Instruments INA237 digital power monitor. Using a 16-bit delta-sigma ADC, the board measures current, bus voltage, power, and internal temperature for an in-line DC load and communicates the measurement data over I2C. It includes a pre-installed 15 mOhm shunt resistor and is well-suited for power-supply monitoring, battery-powered systems, embedded electronics, and development projects requiring detailed electrical measurements.
The breakout provides 2x Qwiic connectors and a 3-pin screw terminal for convenient solderless integration, along with 0.1-inch spaced plated through-hole connections for power, SDA, SCL, and the multi-purpose alert output. Through-hole connections are also provided for using a custom external shunt resistor when the standard 15 mOhm value does not suit the application. Programmable conversion times from 50 us to 4.12 ms, hardware averaging from 1 to 1024 samples and threshold-based alerts allow the INA237 to handle measurement and monitoring tasks with reduced processing demand on the host microcontroller.
Key Features

INA237 Power Monitor: Uses the Texas Instruments INA237 digital current and power-monitoring IC.
16-Bit ADC: Integrated 16-bit delta-sigma ADC supports precise electrical measurements.
Multiple Measurements: Measures DC, bus voltage, power, and internal temperature.
15 mOhm Shunt Resistor: Includes a pre-installed 15 mOhm current-sense resistor for immediate use.
Custom Shunt Support: Through-hole connections allow an external shunt resistor to be fitted for application-specific measurements.
I2C Communication: Provides digital measurement data through an I2C interface for microcontroller integration.
Qwiic Connectivity: Includes 2x Qwiic connectors for solderless connection to compatible Qwiic systems.
Screw-Terminal Connection: 3-pin screw terminal provides a convenient connection point for the monitored DC power path.
Through-Hole Interface: 0.1-inch spaced plated through-holes provide access to power, SDA, SCL, and alert connections.
Programmable Alerts: Can generate alerts for configured voltage, current, power, and temperature thresholds.
Conversion-Ready Alert: Alert output can indicate when a measurement conversion has completed.
Fast Alert Response: Provides an alert response time of approximately 75 us.
Selectable Conversion Time: ADC conversion time can be configured from 50 us to 4.12 ms.
Hardware Averaging: Supports averaging from 1 to 1024 samples to balance response speed and measurement stability.
Open-Drain Alert Output: Multi-purpose open-drain digital output supports event-driven monitoring.
Processor Offloading: Hardware-based measurement, averaging, and threshold functions can reduce continuous processing requirements on the host controller.

Specifications:
INA237 Features

16-Bit Delta-Sigma ADC
Current Monitoring Accuracy:

Offset Voltage: 50 V (max)
Offset Drift: 0.02 V/C (max)
Gain Error 0.3% (max)
Gain Error Drift: 50 ppm/C (max)
Common Mode Rejection: 120 dB (max)

Power Monitoring Accuracy: 1.6% full scale, -40C to +125C (max)
Alert Response Time: 75 S
Common Mode Range: -0.3 V to +85 V
Bus Voltage Sensing Input: 0 V to 85 V
Shunt Full-Scale Differential Range: 163.84 mV / 40.96 mV
2.94MHz high-speed I2C interface.

4 Available I2C Addresses (Selected by solder jumpers)
Default Address: 0x40

Supply Voltage: 2.7 V to 5.5 V

Operational Current: 640 A (typ)
Shutdown Current: 5 A (max)

Qwiic Breakout Features

2x Qwiic Connectors
1x 3-Pin Screw Terminal

Max Power Rating: 85V/10A
IN Shunt Resistor: 10m (Default)
Optional external shunt resistor connections
VBUS isolated from IN by default

0.1″-spaced Through Hole Header

Power (VCC/GND), I2C (SDA/SCL) and Alert

Red Power LED

Applications

DC monitoring
Power-consumption measurement
Battery-powered systems
Power-supply monitoring
Embedded power management
Development-board power analysis
IoT power monitoring
Robotics and motor-control systems
Industrial electronics
Energy-monitoring systems
Prototype power measurement
Over-current and over-voltage monitoring
Temperature-aware power systems
Low-power microcontroller applications

Dimensions