OPA454: Input bias/offset current specification

Hi Jan,

I went through the original OPA454 release documentation and didn't find any explanation why the maximum room temperature Ib was set at +/-100 pA. The data collected at that time shows that it was low for the lots characterized supporting the +/-1.4 pA typical set in the datasheet.

Modern ATE systems are capable of accurate measurment of pA level currents. I suspect that the thought at the time was to set the OPA454 Ib max to a high value such that it would not ever be a production test yield concern. The OPA454 is a very high voltage op amp and the thought may have been that 100 pA is fine for an op amp in that catagory.

Regards, Thomas

PA - Linear Applications Engineering

Hi Thomas,

Thanks for the quick and informative response.

Until now I have been using the OPA129 for this specific application. But, since I need to measure voltages from 0V-50V I have had to create a floating supply for the OPA129 that tracks the measured voltage. This works fine, however, this extra circuitry is quite power hungry (roughly 1W) and takes up considerable space in our test systems.
Since the build rate for these systems is very small it would be acceptable to screen devices for typical IB performance.
Do you by any chance have access to characterization data that could give me an estimate of the mean/stdev for the IB at 85C?
We have purchased a small sample of devices in order to run some bench tests over temperature, but, any additional data would be very helpful.

Sincerely,
Jan

Hi Jan,

I don't have access to current OPA454 production data, but I do have over-temperature Ib graphs from when the product was developed. We don't openly provide this kind of information because it is company confidential, but if your company does have an NDA in place with TI it can be provided to you. Please check on the NDA status.

Please note that our operations are quickly winding down due to the upcoming holidays in the US. Very likely, if we are able to move ahead with providing the information, it won't happen until after the first of the new year.

Regards, Thomas

PA - Linear Applications Engineering

Hi Thomas,

Thanks for assisting me with this. I have sent a request for our NDA status with TI. If we don't have one on file I will have Knowles legal generate one for your approval.

I quess this will push into 2017. How  should I communicate this to you/TI?

Sincerely,

Jan

Hi Thomas,
I do have an NDA in hand for your review. Can I email this directly to you?
Sinerely,
Jan

Hi Jan,

Please send it to the mail address I provided.

Regards, Thomas

PA - Linear Applications Engineering

Hi Thomas,

Sorry for being a bit thick here... but, I am new to TIE2E and can't seem to locate your email.
Could you please resend it?

Sincerely,
Jan

Hi Jan,

No problem. It looks like it didn't list in my previous response. Please use:

kuehl_tom@ti.com

Regards, Thomas
PA - Linear Applications Engineering