ꢀ ꢁꢂ ꢃ ꢄ ꢂ ꢄ ꢅ ꢀꢁ ꢂꢃ ꢄꢂ ꢂꢅ
ꢀ ꢁꢂ ꢃ ꢄ ꢂ ꢆ ꢅ ꢀꢁ ꢂꢃ ꢄꢂ ꢃ
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ꢀ ꢁꢂ ꢃ ꢄ ꢂ ꢇ ꢅ ꢀꢁ ꢂꢃ ꢄꢂ ꢈ
SLUS549C − DECEMBER 2002 − REVISED AUGUST 2004
FUNCTIONAL DESCRIPTION
TIMER FAULT RECOVERY
As shown in Figure 4, bqTINY-II provides a recovery method to deal with timer fault conditions. The following
summarizes this method:
Condition #1: Charge voltage above recharge threshold (V
) and timeout fault occurs
(RCH)
Recovery method: bqTINY-II waits for the battery voltage to fall below the recharge threshold. This could happen
as a result of a load on the battery, self-discharge or battery removal. Once the battery falls below the recharge
threshold, the bqTINY-II clears the fault and starts a new charge cycle. A POR or CE or TTE toggle also clears the
fault.
Condition #2: Charge voltage below recharge threshold (V
) and timeout fault occurs
(RCH)
Recovery method: Under this scenario, the bqTINY-II applies the I
current. This small current is used to detect
(FAULT)
a battery removal condition and remains on as long as the battery voltage stays below the recharge threshold. If the
battery voltage goes above the recharge threshold, then the bqTINY-II disables the I current and executes the
(FAULT)
recovery method described for condition #1. Once the battery falls below the recharge threshold, the bqTINY-II clears
the fault and starts a new charge cycle. A POR or CE or TTE toggle also clears the fault.
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