BQ34Z100-G1: Calculate CC Gain and Floating Point conversion

Yunfeng TANG

Intellectual 300 points

Part Number: BQ34Z100-G1
Other Parts Discussed in Thread: BQSTUDIO,

Hello,

Can you verify my calculate of CC Gain and his Floating Point conversion?

ccGain = current /(avgRawCurrent-(ccOffset + boardOffset) / 16)

Where current = 500mA; avgRawCurrent = 65425; ccOffset = -1347; boardOffset = 3

So ccGain = 0,007632539

And the floating Point for the ccGain, I find 0x611A7A79

Does this floating point is correct? If not what the correct value?

Do you have a calculator to verify this value? Can you give me the calculator?

over 1 year ago

0 Diego over 1 year ago

TI__Mastermind 25510 points

Hi,

Here is a thread to calibrate the device without bqstudio - (10) BQ34Z100-G1: CC Gain, CC Delta. - Power management forum - Power management - TI E2E support forums

However, I recommend using BQstudio to calibrate your device.

Regards,

Evan

0 Yunfeng TANG over 1 year ago in reply to Diego

Intellectual 300 points

Hello,

The link doesn't reply my need. I found the flow chart to do the calibration.

My question is about the floating point conversion.

Does my calculate is ok?

ccGain = 0,007632539 ==> floating Point for the ccGain, I find 0x611A7A79? Is this OK?

Do you have a calculator that I can use to make sure the floating point is correct?

0 Diego over 1 year ago in reply to Yunfeng TANG

TI__Mastermind 25510 points

Hi,

Please allow me sometime to align with my team on this.

Regards,

Evan

0 Yunfeng TANG over 1 year ago in reply to Diego

Intellectual 300 points

OK Thank you

I will give you some more details

CC Gain is 0.256 when I calibrate the current with BqStudio

and the CC Gain in Hex is 0x85152F25

But the CC Gain is below when I do the calibration with a microcontoller

So ccGain = 0,007632539

And the floating Point for the ccGain, I find 0x611A7A79

Please check where is my issue. Why the CC Gain in BqStudio and with microcontroller is different.

0 Diego over 1 year ago in reply to Yunfeng TANG

TI__Mastermind 25510 points

Hi,

Please refer to this thread.

(+) BQ78350R1 SMBUS Floating Point Calculation - Power management forum - Power management - TI E2E support forums

(+) [FAQ] BQ34Z100-G1: Frequently Asked Questions - Power management forum - Power management - TI E2E support forums

Closing this thread to continue on the new thread you opened.

Regards,

Evan

0 Yunfeng TANG over 1 year ago in reply to Diego

Intellectual 300 points

Thank you for your link.

After check my calculate floating point conversion is correct.

So now the problem is CC Gain.

I Have ccGain = 0,007632539. But the ccGain in bqStudio is 0.256.

I calibrate the current with my own microcontroller.

I use below 2 flow chart to do the calibration current. I can't find the correct ccGain.

Are the 2 flow chart correct for the BQ34Z100-G1? Or do you have the correct calibration flow chart?