INA226 Power Monitor

Name: INA226 Power Monitor
Brand: Texas Instruments
Availability: InStock

INA226

Texas Instrumentsic data converter

The INA226 is a 16-bit, ultra-precise current, voltage, and power monitor with an I2C/SMBus interface. It senses bus voltages from 0 to 36 V on the high or low side and reports current and power directly.

Manufacturer datasheet

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In stock

Specifications

Operating Voltage: 2.7 to 5.5 V
Bus Voltage Range: 0 to 36 V
Interface: I2C/SMBus
Resolution: 16 bit
Accuracy: 0.1 %
Supply Current: 330 uA
Operating Temperature Range: -40 to 125 °C
Package Types: VSSOP-10

Pinout

Pin	Name	Functions	Notes
1	A1	GPIO	Address pin; connect to GND, SCL, SDA, or VS
2	A0	GPIO	Address pin; connect to GND, SCL, SDA, or VS
3	Alert	GPIO	Multi-functional alert, open-drain output
4	SDA	I2C	Serial bus data line, open-drain input/output
5	SCL	I2C	Serial bus clock line, open-drain input
6	VS	POWER	Power supply, 2.7 V to 5.5 V
7	GND	GND	Ground
8	VBUS	ADC	Bus voltage input
9	IN-	ADC	Connect to load side of shunt resistor
10	IN+	ADC	Connect to supply side of shunt resistor

Interactive pinout

Highlight:

INA226

Click a pin to copy its name · tap a tag above to spotlight a bus.

Starter code

Community starter examples — minimal, unofficial, and provided to get you wiring fast. Verify against the manufacturer datasheet before relying on them.

Arduino (C++)

arduino

// INA226 current / power monitor — community starter example
// Bus voltage needs no calibration (1.25 mV/LSB); current needs a cal register
// set for your shunt — use the Rob Tillaart 'INA226' library for that.
#include <Wire.h>

const byte ADDR = 0x40;   // A0/A1 -> GND

float readBusVoltage() {
  Wire.beginTransmission(ADDR);
  Wire.write(0x02);                 // bus voltage register
  Wire.endTransmission();
  Wire.requestFrom(ADDR, (byte)2);
  uint16_t raw = (Wire.read() << 8) | Wire.read();
  return raw * 0.00125;             // 1.25 mV/LSB
}

void setup() {
  Serial.begin(115200);
  Wire.begin();
}

void loop() {
  Serial.print("Vbus="); Serial.print(readBusVoltage()); Serial.println(" V");
  delay(1000);
}

MicroPython

python

# INA226 (ESP32) — community starter example
# Bus voltage (no calibration). For current, set the cal register / use a driver.
from machine import Pin, I2C
import time

i2c = I2C(0, scl=Pin(22), sda=Pin(21))
ADDR = 0x40

while True:
    d = i2c.readfrom_mem(ADDR, 0x02, 2)   # bus voltage register
    raw = (d[0] << 8) | d[1]
    print("Vbus", raw * 0.00125, "V")
    time.sleep(1)

Wiring

Pin	Arduino Uno R3	ESP32 DevKitC (WROOM-32)	Notes
VS	+5V	3V3	Logic 2.7-5.5 V
GND	GND	GND
SCL	A5/SCL	GPIO22	I2C clock
SDA	A4/SDA	GPIO21	I2C data
IN+ / IN-	-	-	Across the shunt, in series with the load (up to 36 V bus)
VBUS	-	-	Tie to the bus node being measured

Typical uses

Precise bus voltage / current / power
Battery and supply-rail monitoring