BQ34Z100-R2: Power management forum

Khalid Mahmood

Part Number: BQ34Z100-R2
Other Parts Discussed in Thread: BQ34Z100-G1

Tool/software:

I am looking at a 200 Amp peak and 100 Amp nominal discharge from my battery pack. And I need to use BQ34Z100-R2 which has Battery capacity (max) (MAh) 7000000 but the max input voltage is 125mV at SRN and SRP. I need to ask following two questions.

1) what should be the value of sense resistor in this case it should be 0.625mili Ohm (R=V/I is 125mV/200A) but in the previous post you recommended it should be minimum 2mili ohm for better performance.

2) If the Battery capacity (max) (MAh) 7000000 for BQ34Z100-R2 then how it is being reflected in the hardware design.

Thanks

Khalid Mahmood

25 days ago

0 Evan 24 days ago

TI__Genius 11405 points

Hi Khalid,

This documentation should answer both questions, bq34z100-G1 High Cell Count and High Capacity Applications

Regards,

Evan

0 Khalid Mahmood 24 days ago in reply to Evan

Prodigy 20 points

I have read this document sir. But the limitation for the sense resistor is still problem. The minimum current sense resistor should be 2mohm. But for my calculation I need to low down the sense resistor value that is 0.625mili Ohm 25W (As maximum voltage at the SRN pin should be 125mV and Maximum current is 200A). Should I use some current buffer circuit before applying the voltage to SRN pin? as mentioned in the threat by "JOSHUA ANDERSON" "BQ34Z100-G1: Buffering current sense resistor design review"

(+) BQ34Z100-G1: Buffering current sense resistor design review - Power management forum - Power management - TI E2E support forums

Regards

Khalid Mahmood

+1 Evan 23 days ago in reply to Khalid Mahmood

TI__Genius 11405 points

Hi Khalid,

A 0.625mOhm sense resistor can be used, this limits the minimum current the device can measure to around 16mA.

I am unfamiliar with the design from the e2e thread linked, but as the thread suggest I suggest simulating this circuit and align with the amplifier team on the connections.

Regards,

Evan

0 Khalid Mahmood 23 days ago in reply to Evan

Prodigy 20 points

Hi Evan,

Thanks for your reply. I do understand that,. I hope this will resolve my issue. Now I am going to design the PCB and after testing if i found any problem then I will repost it.

Thanks again for your time.

Khalid Mahmood