INA250: current flow and output mismatch

Showrya Mohan Avrekad Chandregowda

Part Number: INA250
Other Parts Discussed in Thread: DRV103,

Tool/software:

Hello,

I am using INA250A4 and connected to +vs and the one side of the valve, other side of the valve is connected to pin no 5 of DRV103. From INA250A4 I am getting 550mV out which means 275mA of current flowing though the valve according to the datasheet of INA250A4. but when I put multimeter in series( between IN- and the valve) to measure the current it only shows 127mA, if I connect the multimeter on the other side(valve and pin 5 of DRv103), I get 127mA. What might be the problem, is this something obvious, or my connection is not right.?

over 1 year ago

0 Mohamed Hamida over 1 year ago

TI__Expert 6602 points

Hi Showrya,

I am looking into this and will get back to you tomorrow. In the meantime however, it may be beneficial for you to view our TIPL series on using current sense amplifiers. The videos that would be most useful at this stage would be: Example circuits for current sense amplifiers and Shunt resistor layout.

Best,

Mohamed

0 Showrya Mohan Avrekad Chandregowda over 1 year ago

Prodigy 50 points

Hello Mohamed,

any update on the matter would be greatly appreciated.

thank you,

Showrya

0 Mohamed Hamida over 1 year ago in reply to Showrya Mohan Avrekad Chandregowda

TI__Expert 6602 points

HI Showrya,

What does the Vout signal look like? If it is an AC signal, then the DMM would be averaging out the measurement. The INA250 will try to follow the waveform of the Vout signal. The schematic seems correct, however a waveform of the Vout signal on the DRV103 would help.

Best,

Mohamed

0 Showrya Mohan Avrekad Chandregowda over 1 year ago in reply to Mohamed Hamida

Prodigy 50 points

Hello Mohamed,

right now I don't have that issue, issue is it current flowing in ammeter wont match the current flowing through the ammeter, lets say ammeter gives reading of 200mA, according to datasheet it should give 400mV Vout, but it gives 650mV. is gain is 2V/1A or something else.? looking for your fast response!

thanks,

Showrya

0 Mohamed Hamida over 1 year ago in reply to Showrya Mohan Avrekad Chandregowda

TI__Expert 6602 points

Hi Showrya,

Showrya Mohan Avrekad Chandregowda said:
right now I don't have that issue, issue is it current flowing in ammeter wont match the current flowing through the ammeter,

I'm a bit confused by this statement. What is the current before the ammeter and after? Are you saying the ammeter is consuming current?

Best,

Mohamed

0 Mitch M over 1 year ago in reply to Mohamed Hamida

TI__Mastermind 26575 points

Hey Showrya,

I'm just following up on this thread. Were you able to fix this problem? If not, can you please share a schematic so that we can investigate further? If you don't reply, I'll presume that your issue has been solved.

Regards,

Mitch

Amplifiers

Amplifiers forum

INA250: current flow and output mismatch