INA 219 current sensing maximum wattage

[lots o tots]

I have an INA 219 and want to calculate the current, but i dont know if it is too high for the INA219. https://www.adafruit.com/product/904
According to the specs it can monitor at up 26V and up to 3.2A.  the current sense resistor is 2W.

The voltage in the circuit will be 19.5V.  i wanted to be able to run current through this at up to 3A.  exact current value is unknown at the moment.  The load will probably be 50% to 75% duty cycle.

Does the current sense resistor at 2W mean that if i run at 19.5V, i cant sense more than 0.1A without burning the sense resistor? (0.1A x 19.5V = 1.95W).

if i cant monitor anything past 1.95W, i will have to use a low value load only through the resistor like a small LED and just add a correction factor to the real load.  i dont really want to do that if it can be avoided.  Is there something that i can wire into the circuit that has a precise load that will provide a constant voltage, constant current that the INA219 can safely sense.  Also(there will actually be 2 seperate circuits and i want the loads in those 2 circuits to be as close as possible to each other.)
thanks
-LOT

[paulca]

To work out the maximum through the resistor you need to know it's value.  It will drop a certain voltage (used to sense the current) for a given current.  Multiple that voltage by the current to get the power dissipated by the resistor.

So if it's a 0.1Ohm resistor at 3.2A it will drop 320mV.  That is 3.2*320mV ~= 1W.  You might note you can just do  Current² Amps * Resistance Ohms = Power Watts dissipated

Ohms law.

[lots o tots]

I see, so we muliply the current by the voltage drop and not the voltage for the voltage in the circuit, as the rating is for the heat it can dissipate.
interesting
Thanks