Hello,
i have a question about the accuracy of the external temperatur sensor for the bq28z610-r.
Based on this Information from the data sheet:
the internal pullup resistor has a range from 14,4 to 21,6 kR. I did some math and got this result for the temperatur accuracy:
when i also take in account that V_REG has a Range of 1.6 .. 2.0 V and the NTC has also a tolerance i get a uncalibrated accuracy of around +/-5 to +/-10°C for the temperature range of -20 ... 60 °C.
I am really surprised about this result, because it means that the uncalibrated sensor is not suitable for any use of the fuel gauge (e.g. the ambient temperature of 70 °C [not ok] could be measured as 60 °C [barely ok]).
My questions are:
- is my calculation wrong?
- is the internal pullup at TS1 more precise than in the data sheet ?
- did i oversee something?
Best regards
