Texas Instruments BQ2419X I²C Controlled 4.5A Single Cell USB / Adaptor Charger Evaluation Module BQ24195EVM-193 BQ24195EVM-193 Datenbogen
Produktcode
BQ24195EVM-193
0 5 10 15 20 25
30 35 40 45 50 55
V(BAT-SYS) (mV)
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
CURRENT
(A)
4.5
9V
Current
2.8A
4A
-0.6A
3.2A
0.5A
3.6V
3.4V
3.2V
3.4V
3.2V
3.18V
1.2A
1.0A
DPM
DPM
Supplement
Voltage
SYS
VBUS
BAT
ICHG
IIN
ISYS
SLUSB97 – OCTOBER 2012
Figure 17. DPM Response
Supplement Mode
When the system voltage falls below the battery voltage, the BATFET turns on and the BATFET gate is
regulated the gate drive of BATFET so that the minimum BATFET V
regulated the gate drive of BATFET so that the minimum BATFET V
DS
stays at 30mV when the current is low.
This prevents oscillation from entering and exiting the supplement mode. As the discharge current increases, the
BATFET gate is regulated with a higher voltage to reduce R
BATFET gate is regulated with a higher voltage to reduce R
DSON
until the BATFET is in full conduction. At this
point onwards, the BATFET V
DS
linearly increases with discharge current.
shows the V-I curve of the
BATFET gate regulation operation. BATFET turns off to exit supplement mode when the battery is below battery
depletion threshold.
depletion threshold.
Figure 18. BATFET V-I Curve
Battery Charging Management
The bq24195L, bq24195 charges 1-cell Li-Ion battery with up to 2.5A/4.5A charge current for high capacity tablet
battery. The 12m
battery. The 12m
Ω
BATFET improves charging efficiency and minimizes the voltage drop during discharging.
Autonomous Charging Cycle
With battery charging enabled at POR (REG01[5:4]=01), the bq24195L, bq24195 can complete a charging cycle
without host involvement. The device default charging parameters are listed in .
without host involvement. The device default charging parameters are listed in .
22
Copyright © 2012, Texas Instruments Incorporated
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