Verified 2026-10

INA219 High Side DC Current Sensor Breakout - 26V +/-3.2A Max

High-side DC current and bus-voltage monitor on I2C: an INA219 across a 0.1 ohm 1% 2 W shunt, +/-3.2 A at +/-0.8 mA resolution on a bus up to +26 V, powered from 2.7-5.5 V, with STEMMA QT connectors and (since May 2024) a pre-soldered 2-pin terminal block for the measured line; 25.6 x 20.4 x 4.7 mm.

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Logic level3.3 V

Pinout

6 pads, as the vendor numbers them.

#	Name	Function	Signals
1	VIN	Board supply (2.7-5.5 V); the fab file names this net VCC while the silkscreen prints VIN. Supply it at the host's logic level because there is no level shifter	supply, logic reference
2	GND	Common ground for power and logic	ground
3	SCL	I2C clock, with a 10 kOhm pull-up fitted on the board	I2C SCL, input
4	SDA	I2C data, with a 10 kOhm pull-up fitted on the board	I2C SDA, bidirectional
5	VIN-	Negative end of the shunt: connect to the load for high-side sensing, or to board ground for low-side sensing. Duplicated on terminal-block pin 1 (the fab file's J1 pad 1)	shunt negative, measurement input
6	VIN+	Positive end of the shunt: connect to the supply for high-side sensing, or to load ground for low-side sensing. Duplicated on terminal-block pin 2 (J1 pad 2)	shunt positive, measurement input

Buses

Bus	Signals	Pins	Voltage	Note
I2C ×1	SDA, SCL	SDA, SCL

I²C / bus addresses

Address	Bus	Device	Note
0x40	I2C	INA219 current/voltage monitor	7-bit, default with both address jumpers open. Vendor table: A0 bridged -> 0x41, A1 bridged -> 0x44, both bridged -> 0x45. The A0/A1 solder jumpers are on the back of the board, not in the pin row.

Power

Input	2.7-5.5 V on VIN; Adafruit says give it the same voltage as the host's logic level (5 V host -> 5 V, Feather -> 3.3 V). The measured load current does not pass through this pin
Input range	2.7-5.5 V

Shunt and measurement limits from the vendor: 0.1 ohm 1% 2 W sense resistor, +/-320 mV maximum input difference (= +/-3.2 A), 12-bit internal ADC giving 0.8 mA resolution at the full +/-3.2 A range and 0.1 mA at +/-400 mA with the gain at div8, target voltage up to +26 V. Adafruit publishes no board-level quiescent current. Accuracy depends on which chip was fitted: the INA219A is +/-1% total max current error over temperature (+/-0.5% max at 25 C) and the INA219B is +/-0.5% (+/-0.3% at 25 C) - the product page says either variant, in SOT-23 or SOIC, may ship.

Notes

Pin numbers 1-6 are the fab file's JP1 pads in silkscreen order (VIN, GND, SCL, SDA, VIN-, VIN+ left to right), 0.1in pitch; Adafruit prints no numbers on the board. The 2-pin 3.5 mm terminal block is a separate part (J1, pads 1 = VIN-, 2 = VIN+) and has been pre-soldered since 31 May 2024, so on a current board the measured line can land on either the header pads 5/6 or the screws - they are the same two nets, and neither is a polarity in the sense of a diode: VIN+ must face the supply for high-side sensing. Two cautions from the vendor's own guide: switching an inductive load can push the inputs far past the steady-state voltage and damage the chip, and the shunt can be replaced by hand (a 0.01 ohm part gives ~32 A at ~8 mA resolution) which changes the calibration the library assumes. Since 29 Jan 2021 the board is the STEMMA QT shape with four mounting holes; the schematic did not change, only the mechanical outline.

Provenance

Every figure on this page was read from the 4 sources below and last checked on Oct 18, 2026.