ADC RESOLUTION BQ34Z100-G1

Loic

I tested the voltage measurement accuracy on the bq34z100-G1. My power supply only has accuracy to three decimal points on the 6V range, so that is what I used. I varied the supply voltage in 5mV steps and recorded the measure and reported voltage. I also graphed the difference with the scale shown on the right hand side of the graph. All measurements are in mV.

Tom

Tom,

I don't understand why I don't have your good result....

Do you have Voltage divider = 19304mV (Approx) ?

Can you send me your Golden Image .Srec file for test with here?

Thank you,

loïc

The Voltage Divider is 19247. I just used the default srec file and reconfigured it for 4S. Here is the srec from the gauge.

https://e2e.ti.com/cfs-file/__key/communityserver-discussions-components-files/196/8611.0100_5F00_0_5F00_16_2D00_bq34z100G1_5F00_4S.srec

Hi Tom,

I have tested again with you .SREC. so I have the same configuration of you.

I varied the supply voltage in 1mV steps every 2000ms and recorded the measure and reported voltage.All measurements are in mV.

My result is bad, see below:

Now I have an offset and  delay time between supply and reported measured.

Do you have an idea? My BQ is dead?

Loïc

Hi TOM,

I've tested again with a new BQ34Z100-G1 and I have this result : ( with your firmware 0100_0_16-bq34z100G1_4S.srec) :

I don't understand why I have 8 or 12mV of voltage step.....

I will test the accuracy of SOC, can you confirm that this voltage steps are not attributable to SOC accuracy?

Best Regards,

Loïc

Hi,

I've testing now with SLEEP bit = false on PACK CONFIGURATION register. And I have this result:

So, It's better !! ADC step is now between 3/4 mV.

Know you if there is an other parameter who would allow to improve the precision of the ADC?

Best regards, Loïc

Very strange things...

I've changed "Number of series cell" parameter of 4 to 12 and voltage step is changed to 12mV !!?

see below:

Loïc