BQ2060SS Datasheet, PDF (15/59 Pages) Texas Instruments – SBS V1.1-COMPLIANT GAS GAUGE IC

bq2060
www.ti.com
SLUS035E – JANUARY 2000 – REVISED OCTOBER 2005
bq2060 clears the FULLY_CHARGED bit when RelativeStateOfCharge() is less than the programmed Fully
Charged Clear %. The bq2060 broadcasts the fast-charge rate when the FULLY_CHARGED bit is cleared and
voltage and temperature permit. The bq2060 clears the TERMINATE_CHARGE_ALARM when it no longer
detects that the battery is being charged or it no longer detects the termination condition. See Table 6 for a
summary of BatteryStatus() alarm and status bit operation.
Display Port
General
The display port drives a 4- or 5-LED, bar-graph display. The display is activated by a logic signal on the DISP
input. The bq2060 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 bq2060 uses FCC as the full-battery reference; in
absolute mode, it uses DC.
The DMODE bit in Pack Configuration programs bq2060 for the absolute or relative display mode. The LED bit in
Control Mode programs the 4-or 5-LED option. A 5th LED can be used with the 4-LED display option to show
when the battery capacity is ≥ to 100%.
Activation
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. The timer expires and turns off the display whether DISP was brought low momentarily
or held low indefinitely. 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 must occur after the display timer expires. The
bq2060 requires the DISP input to remain stable for a minimum of 250ms to detect the logic state.
If the EDV0 bit is set, the bq2060 disables the LED display. The display is also disabled during a VFC calibration
and should be turned off before entering the low-power storage mode.
Display Modes
In relative mode, each LED output represents 20% or 25% of the RelativeStateOfCharge() value. In absolute
mode, each LED output represents 20% or 25% of the AbsoluteStateOfCharge() value. Table 7 shows the
display operation.
In either mode, the bq2060 blinks the LED display if RemainingCapacity() is less than Remaining
CapacityAlarm(). The display is disabled if EDV0 = 1.
Secondary Protection for Li-Ion
Undervoltage and overvoltage thresholds may be programmed in the byte value Cell Under/Over Voltage EE
0x4a to set a secondary level of protection for Lithium ion cells. The bq2060 checks individual cell voltages for
undervoltage and overvoltage conditions. The bq2060 displays the results in the Pack Status register and
controls the state of the FET control outputs CFC and DFC. any cell voltage is less than the V_UV threshold, the
bq2060 sets the CVUV bit in Pack Status and pulls the DFC pin to a logic low. If any cell voltage is greater than
the V_OV threshold, the bq2060 sets the CVOV bit in Pack Status and pulls the CFC pin to a logic low.
Low-Power Storage Mode
The bq2060 enters low-power mode 5 to 8 s after receiving the Enable Low-Power command. In this mode the
bq2060 consumes less than 10 µA. A rising edge on SMBC, SMBD, or HDQ16 restores the bq2060 to the full
operating mode. The bq2060 does not perform any gas gauge functions during low-power storage mode.
Device Reset
The bq2060 can be reset with commands over the HDQ16 or SMBus. On reset, the bq2060 initializes its internal
registers with the information contained in the configuration EEPROM. The following command sequence
initiates a full bq2060 reset:
Write 0x4f to 0xff5a
Write 0x7d to 0x0000
Write 0x7d to 0x0080
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