DS2745K Maxim Integrated, DS2745K Datasheet - Page 6

• Manufacturer Part Number: DS2745K
• Description: Power Management IC Development Tools
• Manufacturer: Maxim Integrated
• Series: DS2745r

DS2745EVKIT
The Meters Screen displays the latest real-time measurements of cell voltage, temperature, current and
accumulated current with both analog meter readouts and digital values. The sense resistor value used to
calculate the current reading is shown in the current section. Left click on the Update Sense Resistor
button to open the Find Sense Resistor window shown below to edit the value. The Current Offset Bias
Register, Accumulation Bias Register, Accumulated Current Register and Slave Address can all be
updated by left clicking on the appropriate button.
The present state of the PIO bit is shown at the bottom of the window. The user can toggle the value of
the PIO bit by left clicking on the associated button
FIND THE SENSE RESISTOR
The Update Sense Resistor button opens the Find Sense Resistor window. The user can input a sense
resistor value into the Sense Resistor Value text box, or the user can determine the resistance by forcing a
known current and measuring the voltage drop with the DS2745. The resistance value is stored in
software and the program uses this value to convert the voltage difference from the VSS and SNS pins
into milliamps. If this value does not match the value of the external resistor, current measurements will
be inaccurate.
SETTING THE OFFSET
The user can bring up the Set Current Offset Bias Register window by left clicking the Update Offset
button of the Meters Tab. The Calibrate Offset button allows the software to auto-detect the appropriate
Current Offset Bias Register value based on the Current Reading. The auto-detection should be
performed while the pack is disconnected and there is no current flow. The process takes approximately
6 of 11