INA381: Gain error and other questions

na na78

Part Number: INA381

1.
Please tell us how to estimate gain error considering temperature drift.

For example, Gain error is offered as 1% as maximum.
Is this value maximum over all opertational temperature range?

Should we consider temperture drift of gain error in addioton even if the maximum 1% gain error is already considered?

2.
Regarding to maximum current consumption with itself, it is 450uA as maximum over operatinal temperature. Is it correct?

3.
When we use multiple devices in same use, is it be possible to connect CMPREF each other at same reference point?

BestRegards

over 8 years ago

0 Patrick Simmons over 8 years ago

TI__Mastermind 26335 points

Hello na na78,

Thanks for reaching out on the forum.

According to the formula posted below, Gain error = 1 + 20/10000*(abs(25-system temperature)). 1.2% is the worst expected over a -40 to 125ᵒC range.

Yes, over the range of -40 to 125ᵒC, 450uA is the highest quiescent current we expect from any device we ship out.
Yes, it is possible to connect multiple device CMPREF pins together

0 na na78 over 8 years ago in reply to Patrick Simmons

Guru 16770 points

Hi Patrick

Thank you for your reply.

Regarding to question 1, what is the constant of "TempCo"?
Why did you consider it as 20 in your calculation of gain error?

BestRegards

0 Patrick Simmons over 8 years ago in reply to na na78

TI__Mastermind 26335 points

Hello na na78,

TempCo, short for temperature coefficient is the max value extracted from the datasheet specification "Gain error vs temperature" shown in the table below (section 6.5 of the datasheet).

If you would like more information on this, I would recommend watching the following tutorial video:

https://training.ti.com/getting-started-current-sense-amplifiers-session-10-understanding-temperature-related-errors?cu=456802

Amplifiers

Amplifiers forum

INA381: Gain error and other questions