INA220: INA 220 negative current calculate

Nanfang Liao

Intellectual 2085 points

Part Number: INA220
Other Parts Discussed in Thread: INA200

Hello,

We can calculate positive current using formula below. How do we calcuate negative current. My customer want to read the negative current, the register value of 0x01 exceedings 32000, i don't know how to use this value, the shunt resistor is 0.01ohm, and the calibrataion value is set to 20480, thanks

Regards,

Nanfang

over 8 years ago

0 Carolus Andrews over 8 years ago

TI__Mastermind 22275 points

Hi Nanfang,

the image you posted isn't showing up. Could you try to repost it?

Carolus

0 Mayrim Verdejo over 8 years ago

TI__Genius 15760 points

Hi Nanfang,

There is no different formulas for negative numbers. The difference will be that the numbers will be stored in 2's complement format. You can see this in Current Register section 8.6.3.4. Refer t section 8.6.3.1 as well for 2's complement info.

0 Nanfang Liao over 8 years ago in reply to Mayrim Verdejo

TI__Intellectual 2085 points

Hello Mayrim,

Thanks, I can't find section 8.6.3.4/8.6.3.1 in our datasheet, can you tell me which document do you use?

Regards,
Nanfang

0 Mayrim Verdejo over 8 years ago in reply to Nanfang Liao

TI__Genius 15760 points

Hi Nanfang,

I am referring to INA200 datasheet. Link below:

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INA220: INA 220 negative current calculate