INA181: why limitation on measurement current to 100A INA181

Olrik Maier

Part Number: INA181
Other Parts Discussed in Thread: , INA293

Hi Amplifier Team,

my customer is planing to use INA181 or INA181-Q1 for current measurement in a BLDC 18V system.. PWM frequency is 80kHz.

In the design tool on TI.com the max current is limit to 100A.

Isn't it possible to measure 180A ?

Best wishes,

Olrik

over 3 years ago

+1 Carolus Andrews over 3 years ago

TI__Mastermind 22530 points

Olrik,

Provided the system is designed correctly, then yes, 180A is achievable. The variables on the current sensing tool are limited to more popular application ranges to help minimize ranging/error issues when the full scale error plot is rendered. Another example here would be that a shunt of <1mΩ may also be selected, and WILL need to be used for currents of this type of magnitude.

0 DHarmon over 3 years ago in reply to Carolus Andrews

TI__Genius 16430 points

Olrik,

You can use our Current Sense Amplifier Comparison and Error Tool (Rev. D) to evaluate error on ranges outside those available in the on-line widget.

0 Olrik Maier over 3 years ago

TI__Expert 5020 points

Hi Dan,

thanks for sending the Current Sense ... Tool.

It's great.

What I figured out that when entering values with comma etc in the System Operating Conditions it seems some Cells are Formatted as Date. For example Supply voltage entering 3.3 it jumps to 03. Mrz. The Format Cell is protected in the sheet so I can't change to number format.

Best wishes,

Olrik

0 Carolus Andrews over 3 years ago in reply to Olrik Maier

TI__Mastermind 22530 points

Olrik,

Odd, can you share specifically where you pulled this file from? I pulled the latest version from the INA293 product folder (where my browser happened to be at the moment :) and its fine. Did you pull it from the INA181 product folder?:

I've manually inserted the file I downloaded into this post as well for convenience. sbor020d (1).zip

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INA181: why limitation on measurement current to 100A INA181