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One last point in this thread is the calculation of junction temperature for INA3221. The datasheet is already shared above.

There are three contributors when it comes to power.

1- Quiescent supply power

2- Input bias power

3- Shunt measurement power

First is the Quiescent supply power. According to datasheet, the Quiescent current is between 350 uA to 450 uA. Let's take the mid value which is

equal to 400 uA.

Supply Quiescent power: IQ x Vs = 400 uA x 5 V =  2 mW

Second is the input bias current.

Input bias current at IN+ = 10 uA

Input bias current at IN- = 10 || 670  μA || kΩ

I am taking 10 uA as input bias current.

The value of shunt resistor is 0.39 mOhm and the shunt resistor voltage is 140 mV. Can I take 70 mV as common mode voltage ? Please comment of the value of common mode voltage (VCM)

Input pin power (for 2 pins): 2 x IN+ x VCM =  2 x 10 uA x 70 mV = 1.4 uW

Thirds is the shunt measurement power.

Vbus measurement power: (VCM/Vbus_Impedance)*VCM =  0.5 W

The total power will be the sum of all three contributions which is almost equal to 0.5 W.

Junction-to-ambient thermal resistance according to section 7.4 of datasheet is 36.5 degC/W

The junction temperature will be equal to ambient temperature (consider 40 degC) + 0.5 W x 36.5 degC/W = 58.25 degC.