Hello,
We have developed a charger for 4s battery pack using BQ25713RSNR.The charge current is 2A max with switching frequency of 800kHz.
System setup:
input:12V output:16.4V charging current:2Amax.
when using BQ studio to test hardware the input current measurement seems to have non linear offset. The readings table is provided in the attachments.
The shunt resistor is 10mohms with part number:WSLP1206R0100FEA
RC filter are 4.99ohms PN:CR0402AJW-472GAS and 33pf PN:GRM1555C1H330FA01D
Shunt resistor is placed close to the IC with kelvin connection.
Kindly review the design
Attachments
1)schematic pdf
2) layout pdf top layer
3)screenshot of the PCB layout to show the placement of shunt resistor
SCH:
TOP Cu layer PDF:
Test Readings :
screenshot of PCB layout:
Current path and sense path highlighted: