You asked for it and here it is! A version of my improved INA3221 breakout board with no sense resistors populated. You can solder on your own sense resistors with the value you want, or you can use external (high current) shunts.

What is it?

• improved INA3221 3 channel voltage and current sensor breakout board
• allows 3 separate power supplies
• unpopulated sense resistors, so that you can solder on your own with the value you want

Specifications

• Size: 30 x 26mm
• Supply Voltage: 2.7 - 5.5V
• Supply Current: 350 µA typical (INA3221)
• Sense Voltage: 0 - 26V, 8mV resolution
• Sense Current: depends on sense resistor / shunt values
• Sense Resistors: unpopulated, 3 resistors (SMD 2512 (imperial) / 6332 (metric)) or external shunts required
• I2C Addresses: 4 (0x40 (default) - 0x43) selectable by solder jumper or A0 pin, see INA3221 datasheet

See documentation link below for more details on this board.

Why did you make it?

The commonly available INA3221 breakout board has a design flaw where all 3 channels use the same power supply. I wanted to fix that and make an improved version available.

What makes it special?

My version implements the example circuit from the INA3221 datasheet and therefore allows 3 different power supplies; one per channel.

Additional sense resistors

You can now select additional sense resistors with this product. This includes 3 sense resistors (SMD 2512 (imperial) / 6332 (metric), 3 Watt).

Please select which resistor value you want, and whether you want me to solder the resistors onto the board or you want them separate.

Available resistor values:

0.100 Ohm

0.075 Ohm

0.050 Ohm

0.025 Ohm

A version of this module with 0.010 Ohm resistors already populated is available here: https://www.tindie.com/products/yesyes/improved-ina3221-breakout-3-power-supplies-001ohm/