Datasheet

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DISPLAY PORT
General
Activation
Display Modes
bq2084-V143
SLUS732 – SEPTEMBER 2006
The display port drives a 3-, 4-, or 5-LED bar-graph display. The display is activated by a logic signal on the
DISP input. The bq2084-V143 can display RM in either a relative or absolute mode with each LED representing
a percentage of the full-battery reference. In relative mode, the bq2084-V143 uses FCC as the full-battery
reference; in absolute mode, it uses Design Capacity (DC). The DMODE bit in Pack Configuration DF 0x28
programs the bq2084-V143 for the absolute or relative display mode. The LED bits program the 3-, 4-, or 5-LED
option.
The display may be activated at any time by a high-to-low transition on the DISP input. This is usually
accomplished with a pullup resistor and a pushbutton switch. Detection of the transition activates the display and
starts a 4-s display timer. Reactivation of the display requires that the DISP input return to a logic-high state and
then transition low again. The second high-to-low transition can be detected only after the display timer expires.
If unused, the DISP input must be pulled up to VCC. If the EDV0 bit is set, the bq2084-V143 disables the LED
display.
In relative mode, each LED output represents 20%, 25%, or 33% of the RelativeStateOfCharge() value. In
absolute mode, each LED output represents 20%, 25% or 33% of the AbsoluteStateOfCharge() value. Table 7
shows the display options for 5 LEDs, for 4 LEDs, Table 8 and Table 9 for 3 LEDs. In either mode, the
bq2084-V143 blinks the LED display if RemainingCapacity() is less than Remaining CapacityAlarm(). The
display is disabled if EDV0 = 1.
Table 7. Display Mode for Five LEDs
CONDITION
FIVE-LED DISPLAY OPTION
RELATIVE OR ABSOLUTE
StateOfCharge() LED1 LED2 LED3 LED4 LED5
EDV0 = 1 OFF OFF OFF OFF OFF
<20% ON OFF OFF OFF OFF
≤ 20%, < 40% ON ON OFF OFF OFF
≤ 40%, < 60% ON ON ON OFF OFF
≤ 60%, < 80% ON ON ON ON OFF
≤ 80% ON ON ON ON ON
Table 8. Display Mode for Four LEDs
CONDITION
FOUR-LED DISPLAY OPTION
RELATIVE OR ABSOLUTE
StateOfCharge() LED1 LED2 LED3 LED4
EDV0 = 1 OFF OFF OFF OFF
<25% ON OFF OFF OFF
≤ 25%, < 50% ON ON OFF OFF
≤ 50%, < 75% ON ON ON OFF
≤ 75% ON ON ON ON
Table 9. Display Mode for Three LEDs
CONDITION
THREE-LED DISPLAY OPTION
RELATIVE OR ABSOLUTE
StateOfCharge() LED1 LED2 LED3
EDV0 = 1 OFF OFF OFF
<34% ON OFF OFF
20
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