What makes the resistors on an SRN and an SRP line?

[Marina23]

What make the resistors on a SRN and a SRP line?

Hello,

i have a question regaring the bq34z100-g1 from ti. The bq34z100-G1 measures the cell voltage, temperature, and current to determine the battery SOC based in the Impedance Track algorithm (refer to Theory and Implementation of Impedance Track Battery Fuel-Gauging
Algorithm Application Report [SLUA450] for more information). The bq34z100-G1 monitors charge and discharge activity by sensing the voltage across a small-value resistor (see attachment R20) between the SRP and SRN pins.

What making the resistors R18 and R19 ?

Grretings, Marina23

View attachment bq34z100-g1_Modul.pdf

 

[dimmich]

Re: What make the resistors on a SRN and a SRP line?

Your circuit is drawn not correctly. R20 conclusions should not both be shorted. One terminal must be connected to battery minus, the other with a minus output circuit. See page 46 of datascheet:
https://www.ti.com.cn/cn/lit/ds/symlink/bq34z100-g1.pdf

R18 R19 together with capacitors C7, C8 - lowpass filter to suppress high frequency noise. Also, if R20 will burn, R18 and R19 will protect the input of the chip from high current, and possibly chip will not burn.