BQ2406X Datasheet, PDF (11/31 Pages) Texas Instruments – 1A SINGLE-CHIP Li-Ion/Li-Pol CHARGE MANAGEMENT IC WITH THERMAL REGULATION

bq2406x
www.ti.com
OPERATING MODES
SLUS689 – JUNE 2006
Power Down
The bq2406x family remains in a power-down mode when the input power voltage (IN) is below the power-down
threshold V_(PDWN). During the power down mode all IC functions are off, and the host commands at the control
pins are not interpreted. The integrated power mosfet connected between IN and OUT pins is off, the status
output pins STAT1 and STAT2 are set to high impedance mode and PG output is set to the high impedance
state.
The power down mode is entered from any other state, if the input power V(IN) falls below the voltage threshold
V_(PDWN).
Sleep Mode
The bq2406x enters the sleep mode when the input power voltage (IN) is above the power down threshold
V(PDWN) but still lower than the input power detection threshold, V(IN) < V(OUT) + V_IN(DT).
During the sleep mode the charger is off, and the host commands at the control pins are not interpreted. The
integrated power mosfet connected between IN and OUT pins is off, the status output pins STAT1 and STAT2
are set to the high impedance state and the PG output indicates input power not detected.
The sleep mode is entered from any other state, if the input power (IN) is not detected.
Power-On-Reset Mode
The input power is detected when the input voltage V(IN) > V(OUT) + V_IN(DT). When the input power is detected
the bq2460x transitions from the sleep mode to the power-on-reset mode. In this mode of operation an internal
timer T_(POR) is started and internal blocks are reset (power-on-reset). Until the timer expires the STAT1 and
STAT2 outputs indicate charger OFF, and the PG output indicates the input power status as not detected.
At the end of the power-on-reset delay the internal comparators are enabled, and the STAT1, STAT2 and PG
pins are active.
Stand-By Mode
In the bq24031/2/3/6 the stand-by mode is started at the end of the power-on-reset phase, if the input power is
detected and CE = HI. In the stand-by mode selected blocks in the IC are operational, and the control logic
monitors system status and control pins to define if the charger will set to on or off mode. The quiescent current
required in stand-by mode is 100 µA typical.
The stand-by mode is entered from any other state, if CE = HI. If the CE pin is not available the bq2406x enters
the begin charge mode at the end of the power-on-reset phase.
Begin Charge Mode
All blocks in the IC are powered up, and the bq2406x is ready to start charging the battery pack. A new charge
cycle is started when the control logic decides that all conditions required to enable a new charge cycle are met.
During the begin charge phase all timers are reset, after that the IC enters the charging mode.
Charging Mode
When the charging mode is active the bq2406x executes the charging algorithm, as described in the state
machine diagram, Figure 4.
Suspend Mode
The suspend mode is entered from any other state when the pack temperature is not within the valid
temperature range. During the suspend mode the charger is set to off, but the timers are not reset.
The normal charging mode resumes when the pack temperature is within range.
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