According to the datasheet for the MAX1737
www.analog.com/.../MAX1737.pdf
between pins CS (Battery Current-Sense Positive Input) and BATT (Battery Current-Sense Negative Input) a current sense resistor R18 is used to set the full-scale charging current (IFSI) by the equation:
IFSI = 0.2V / R18
where 0.2V represents the voltage between the CS and BATT pins.
However the datasheet for the MAX1737 Evaluation Kit
www.analog.com/.../MAX1737EVKIT.pdf
shows two additional resistors R19 and R20 between pin CS and R18 and between pin BATT and R18, respectively.
The value of these two additional resistors in the evaluation board are both 4.7Ω which is much larger than the value of R18 which is 0.1Ω.
I am debugging a board with the same resistor configuration (although different values) so I would like to know if there are any design equations and/or approximations used when selecting the values for additional resistors R19 and R20. I would like to be able to calculate the voltages I should be seeing across these additional resistors.
