Datasheet

V
OUT
4 .4 V
4 .3 V
~ 3 .6 V
DPMloopactive
Supplement
Mode
I
BAT
I
IN
-100mA
0mA
150mA
0mA
150mA
400mA
0mA
250mA
400mA
500mA
I
OUT
bq24230
bq24232
SLUS821E –OCTOBER 2008–REVISED JANUARY 2014 www.ti.com
Figure 27. bq2423x DPPM and Battery Supplement Modes
(V
OREG
= 4.4 V, V
BAT
= 3.6 V, I
LIM
=400 mA, I
CHG
= 150 mA)
Input Source Not Connected
When no source is connected to the IN input, OUT is powered strictly from the battery. During this mode, the
current into OUT is unregulated, similar to Battery Supplement Mode; however, the short-circuit circuitry is active.
If the OUT voltage falls below the BAT voltage by 250 mV for longer than t
DGL(SC2)
, OUT is turned off. The short-
circuit recovery timer then starts counting. After t
REC(SC2)
, OUT turns on and attempts to restart. If the short-circuit
remains, OUT is turned off and the counter restarts. This ON/OFF cycle continues until the overload condition is
removed.
Battery Charging
Set CE low to initiate battery charging. First, the device checks for a short circuit on the BAT pin by sourcing
I
BAT(SC)
to the battery and monitoring the voltage. When the BAT voltage exceeds V
BAT(SC)
, the battery charging
continues. The battery is charged in three phases: conditioning precharge, constant-current fast charge (current
regulation), and a constant-voltage tapering (voltage regulation). In all charge phases, an internal control loop
monitors the IC junction temperature and reduces the charge current if an internal temperature threshold is
exceeded.
Figure 28 illustrates a normal Li-ion charge cycle using the bq2423x:
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