INA3221: Power Rating of the Sense Resistor

Sam Durai

Part Number: INA3221

Tool/software:

Hi Team,

I am using the current sensor part INA3221AIRGVR in my design. I want to know the way to select power rating of the sense resistor, that we are using for this. Where can I get this guideline? The maximum current flowing through the current sense resistor is 13A with 5V.

1 day ago

+1 Clemens Ladisch 1 day ago

Guru 284810 points

The power dissipated in the resistor is V × I = R × I².

0 Sam Durai 1 day ago in reply to Clemens Ladisch

Intellectual 260 points

Thanks Clemens

0 Louis L 1 day ago in reply to Sam Durai

TI__Expert 4330 points

Sam,

Along with Clemens' equation, you could reference a couple of our training videos located here. I specifically suggest "How to choose a shunt resistor" and "Shunt resistor layout" under the Current Sense Amplifier Applications section.

Please let us know if you have any other questions.

Louis

0 Sam Durai 15 hours ago in reply to Clemens Ladisch

Intellectual 260 points

Hi Clemens,

I have one more doubt. The load device in my board requires 65W (5V @ 13A). I have connected the current sense resistor with 4W power rating between power supply and load. The 4W current sense resistor does not allow 65W of power to flow through it right?

The current sense resistor value is 5mOhm.

Amplifiers

Amplifiers forum

INA3221: Power Rating of the Sense Resistor