DS2764K Maxim Integrated, DS2764K Datasheet - Page 6

• Manufacturer Part Number: DS2764K
• Description: Power Management IC Development Tools
• Manufacturer: Maxim Integrated
• Series: DS2764r

DS2764EVKIT+
METERS TAB
The Meters Screen displays the latest real-time measurements of cell voltage, temperature, current and
accumulated charge 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 it or go to the sense resistor
sub-tab under Pack Info to change this value. The Calibrate Offset button in the current section allows the
user to zero the current measurements under the conditions of their circuit. Left clicking this button will
begin the automatic calibration procedure. Calibration should be performed while the pack is
disconnected and there is no current flow. The next 32 readings will be averaged and the offset eliminated
by adjusting the Current Offset Register (location 0x33h) automatically. The process takes approximately
20 seconds.
The user can bring up the Update Current Accumulator window by left clicking the Set ACR button. This
window allows the user to enter values for the Current Accumulator Register and Rated Battery Capacity
in mAH. Rated Battery Capacity is used to determine full scale range on the Charge Remaining Meter
only. It has no effect on device operation.
The present states of the Charge Control and Discharge Control pins are shown at the bottom left of the
window. These outputs are active low and drive two control FETs allowing charging and discharging of
the cell pack. The Charge Control pin can be controlled manually by left clicking the Disable/Enable
Charging button and will be forced high automatically by either an Overvoltage or Charge Overcurrent
condition. The Discharge Control pin can also be controlled manually with the Disable/Enable
Discharging button and will be forced high automatically by either an Undervoltage or Discharge
Overcurrent condition. The present state of each of the four possible flag conditions (Overvoltage,
Undervoltage, Charge Overcurrent, and Discharge Overcurrent) are represented by LEDs inside the
voltage and current sections of the window. The corresponding LED will be green while the flag is in the
cleared state. If conditions cause a flag to be tripped, the LED will turn red and a button will appear that
6 of 14