INA185-Q1: Need assistance in designing current sense amplifier

Phanidhar M

Part Number: INA185-Q1
Other Parts Discussed in Thread: INA185

Tool/software:

Hello,

We are designing a master slave BMS. The master will have to get the pack current reading and take necessary action for current faults (OCC,OCD and SCD). We would like to use INA185-Q1 current sense amplifier for this purpose. As per the documentation, I understood that the signal from the amplifier is fed to the ADC of an MCU. The master has an MCU which is powered with 12V and this current sense amplifier is connected to the pack negative. To use this amplifier, is it better to use an isolator between master and current sense block? Or should the pack- and the master ground be connected together? I am sharing the relevant block diagram below

Thank you

over 1 year ago

0 Holly R over 1 year ago

TI__Expert 6225 points

Hi Phanidhar,

Either method will be ok, but the easier method is to ensure that the master, pack, and INA185 all have the same ground.

Best,

Holly

0 Phanidhar M over 1 year ago in reply to Holly R

Prodigy 60 points

Thank you for your response. I have another question. For OCC and OCD faults, the master would take the action directly(i.e. turn off the contactor). Since SCD fault requires very fast action, I would like to use a dedicated hardware comparator which takes action. Is this method recommended for this purpose? Also, could you suggest any other methods for this?

Thank you

+1 Holly R over 1 year ago in reply to Phanidhar M

TI__Expert 6225 points

Hello,

What you have suggested is our recommended method for doing this. Please see the snippet from section 6.3.1 of the datasheet below.

We have a large portfolio of comparators I would recommend you look at. The following link allows you to filter our devices based on what specifications you need. https://www.ti.com/amplifier-circuit/comparators/products.html

Best,

Holly

0 Phanidhar M over 1 year ago in reply to Holly R

Prodigy 60 points

Hello,

Thank you for your response. This suggestion came up while I was searching for methods of fault detection.

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INA185-Q1: Need assistance in designing current sense amplifier