INA826: Mistake in datasheet?

Nicolas Locatelli

Part Number: INA826
Other Parts Discussed in Thread: , INA828, INA129

Hi,

can you tell me if there is a mistake in the INA826 datasheet? They show a pin description at the beginning, but then, in the layout example in figure 73, the pinout is different.

It occurs that I had some PCBs built and the section depending on the INA826 does not work. That is how I came to post this question.

Thanks

over 7 years ago

0 Dennis Goeke over 7 years ago

TI__Genius 11135 points

Nicolas

You are correct, this is an error in the data sheet. Figure 73 is incorrect; all of the other figures are correct.
I will notify the document team and get this updated.
For an example of a suggested layout you can use the INA826EVM. I would be happy to send you one if you think it would be helpful. Here is the link to the tool page:
www.ti.com/.../INA826EVM

Dennis

0 Tim Green1 over 7 years ago

TI__Expert 6275 points

Another option for SOIC 8 pin compatibility on your first PCBs is INA828 (slightly different gain equation) or INA129 (same gain equation). Both of these parts require a bit more Iq and are wider bandwidth.

0 Nicolas Locatelli over 7 years ago in reply to Tim Green1

Prodigy 40 points

Can you tell me if the IC in the picture attached is the INA826? I got it from DigiKey. Why doesn't it say INA826?

I really can't make it work with the right layout. I put 1V at (IN+ - IN-), Gain = 1, Vref = GND, and I get at the output 0,06V. Of course there are no shortcuts, and the voltage supply is ok.

The PCB is son simple I can't believe it doesn't work. And I tested twice, in different PCBs.

0 Dennis Goeke over 7 years ago in reply to Nicolas Locatelli

TI__Genius 11135 points

Nicolas

The part is an INA826. The code IPDI is the identifier.
What supply voltage are you using?

Dennis

0 Nicolas Locatelli over 7 years ago in reply to Dennis Goeke

Prodigy 40 points

The supply voltage is single sided: 5V at VS+ and GND at VS-.

Vref is also tied to GND.

No resistance as Rg, which means G = 1.

0 kai klaas69 over 7 years ago in reply to Nicolas Locatelli

Guru 140200 points

Hi Nicolas,

what is the common mode input voltage? What is the differential input voltage? Are both input voltages referenced to GND? Have you provided a current path to GND for the input bias currents?

Kai

0 Nicolas Locatelli over 7 years ago in reply to kai klaas69

Prodigy 40 points

That was it. The input bias currents. I provided a path to GND on both inputs and problem solved.

Thanks, I would probably not have solved it without your help.

Nicolas

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INA826: Mistake in datasheet?