Texas Instruments BQ51050BEVM-764 Evaluation Module BQ51050BEVM-764 BQ51050BEVM-764 Datenbogen
Produktcode
BQ51050BEVM-764
Regulation
voltage
Precharge
Phase
Current Regulation
Phase
Voltage Regulation
Phase
Charge Current
Battery
Voltage
Rectifier voltage
V
BAT
+ 300mV
V
LOWV
(3.0V)
20% Precharge to
Close Pack Protector
V
RECT -TRACK
Tx Turned
OFF
Termination
Current
Threshold
I
BATSHORT
V
RECT-REG
-
V
BAT -SHORT
(1.0V)
I
PRECHARGE
Exits
V
RECT -TRACK
I
BULK
I
BULK
35% of
SLUSB42D – JULY 2012 – REVISED JANUARY 2014
Battery Charge Profile
The rectifier voltage follows BAT voltage plus 300 mV for any battery voltage above V
LOWV
to full regulation
voltage and most of the taper charging phase. If the battery voltage is below V
LOWV
or I
CHG
is less than 35% of
fast charge current during taper mode, the rectifier voltage increases to V
RECT-REG
. The charge profile is shown in
.
Figure 21. Li-Ion Battery Charger Profile
The battery is charged in three phases: precharge, fast-charge constant current and constant voltage. In all
charge phases, an internal control loop monitors the IC junction temperature and reduces the charge current if
the internal temperature threshold is exceeded. Additionally, a voltage-based battery pack thermistor monitoring
input (TS) is included that monitors battery temperature for safe charging. The TS function for bq5105x is JEITA
compatible.
charge phases, an internal control loop monitors the IC junction temperature and reduces the charge current if
the internal temperature threshold is exceeded. Additionally, a voltage-based battery pack thermistor monitoring
input (TS) is included that monitors battery temperature for safe charging. The TS function for bq5105x is JEITA
compatible.
Battery Charging Process
Precharge Mode (V
BAT
≤ V
LOWV
)
The bq5105X enters pre-charge mode when V
BAT
≤ V
LOWV
. Upon entering precharge mode, battery charge
current limit is set to I
PRECHARGE
. During pre-charge mode, the charge current is
regulated to 20% of the fast
charge current (I
BULK
) setting.
If the battery is deeply discharged or shorted (V
BAT
< V
BAT-SHORT
), the bq5105X applies I
BAT-SHORT
current to bring
the battery voltage up to acceptable charging levels. Once the battery rises above V
BAT-SHORT
, the charge current
is regulated to I
PRECHARGE
.
Under normal conditions, the time spent in this pre-charge region is a very short percentage of the total charging
time and this does not affect the overall charging efficiency for very long.
time and this does not affect the overall charging efficiency for very long.
18
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