Datasheet

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
3.18V
1.2A
1.0A
DPM DPM
Supplement
Voltage
SYS
VBUS
BAT
ICHG
IIN
ISYS
bq24190, bq24192
bq24192I, bq24193
www.ti.com SLUSAW5A –JANUARY 2012–REVISED OCTOBER 2012
Figure 27. 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
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
DSON
until the BATFET is in full conduction. At this
point onwards, the BATFET V
DS
linearly increases with discharge current. Figure 28 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.
Figure 28. BATFET V-I Curve
Battery Charging Management
The bq24190, bq24192, bq24192I, bq24193 charges 1-cell Li-Ion battery with up to 4.5A charge current for high
capacity tablet battery. The 12mΩ BATFET improves charging efficiency and minimizes the voltage drop during
discharging.
Copyright © 2012, Texas Instruments Incorporated Submit Documentation Feedback 25
Product Folder Links: bq24190 bq24192 bq24192I bq24193