ꢀ ꢁ
ꢀ ꢁ
ꢀ ꢁ
ꢂꢃ ꢄꢂ ꢄ ꢅ
ꢂꢃ ꢄꢂ ꢆ ꢅ
ꢂ ꢃꢄ ꢂ ꢇꢅ
ꢀ ꢁ
ꢀ ꢁ
ꢀ ꢁ
ꢂ
ꢂ
ꢂ
ꢃ
ꢃ
ꢃ
ꢄ
ꢄ
ꢄ
ꢂ
ꢂ
ꢂ
ꢂ
ꢃ
ꢈ
ꢅ
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SLUS549C − DECEMBER 2002 − REVISED AUGUST 2004
FUNCTIONAL DESCRIPTION
SLEEP MODE
The bqTINY-II enters the low-power sleep mode if both AC and USB are removed from the circuit. This feature
prevents draining the battery during the absence of input supply.
CHARGE STATUS OUTPUTS
The open-drain STAT1 and STAT2 outputs indicate various charger operations as shown in the following table. These
status pins can be used to drive LEDs or communicate to the host processor. Note that OFF indicates the open-drain
transistor is turned off.
Table 1. Status Pins Summary
CHARGE STATE
Precharge in progress
STAT1
ON
STAT2
ON
Fast charge in progress
Charge done
ON
OFF
ON
OFF
OFF
OFF
OFF
Charge suspend (temperature)
Timer fault
OFF
OFF
OFF
Sleep mode
(ꢃ) OFF means the open-drain output transistor on the STAT1 and
STAT2 pins is in an off state.
PG OUTPUT
The open-drain PG (Power Good) indicates when the AC adapter is present. The output turns ON when a valid
voltage is detected. This output is turned off in the sleep mode. The PG pin can be used to drive an LED or
communicate to the host processor.
CE INPUT (CHARGE ENABLE)
The CE digital input is used to disable or enable the charge process. A low-level signal on this pin enables the charge
and a high-level signal disables the charge and places the device in a low-power mode. A high-to-low transition on
this pin also resets all timers and timer fault conditions. Note that this applies to both AC and USB charging.
TTE INPUT (TIMER AND TERMINATION ENABLE)
The TTE digital input is used to disable or enable the fast-charge timer and charge taper detection. A low-level signal
on this pin enables the fast-charge timer and taper timer and a high-level signal disables this feature. Note that this
applies to both AC and USB charging.
THERMAL SHUTDOWN AND PROTECTION
The bqTINY-II monitors the junction temperature, T , of the die and suspends charging if T exceeds T .
(SHTDWN)
J
J
Charging resumes when T falls below T
by approximately 15ꢂ C.
J
(SHTDWN)
TE INPUT (TIMER ENABLED)
The TE digital input is used to disable or enable the fast-charge timer. A low-level signal on this pin enables the
fast-charge timer and a high-level signal disables this feature.
Note that this applies to both AC and USB charging.
14
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