INA282 External Reference Output / Nonsymmetrical Current

Joel Afanou

Other Parts Discussed in Thread: INA282

Hi,

We are currently using the INA282 in an application with an external reference output(same configuration as figure36) of 2.048V. The measured current is nonsymmetrical (2A same waveform as Buck current in inductor ).

We have performed the following measurements at the INA282 output:

1- No current: Voutput=2.048V

2-Current of 2A: Voutput= 2.18V

We thought to obtain Voutput =3.248V with Rshunt=0.012Ohm using the following equation Voutput=(Isense * Rshunt *50)+ 2.048; can you tell me if this equation is applicable with a nonsymmetrical current?

We have the same schematics with a symmetrical current, this equation is applicable for this configuration?

Thanks for your reply

Joël Afanou

over 9 years ago

0 Deepak%20murali over 9 years ago

Expert 1095 points

Hi Joel Afanou,

Power supply (voltage between pin 6 and pin 2) must be greater than Voutput=(Isense * Rshunt *50)+ 2.048. Eg: 5V. Otherwise the INA will get saturated. And it is strange that your O/P is more than the power supply.

I tried your circuit in TINA software. I have attached it also4505.INA282.TSC

0 Joel Afanou over 9 years ago in reply to Deepak%20murali

Prodigy 20 points

Hi Deepak Murali,

Thanks for your reply. We have followed TI recommendations since the power supply is set to 12V.

Regards,

Joel Afanou

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INA282 External Reference Output / Nonsymmetrical Current