bq2057, bq2057C
bq2057T, bq2057W
SLUS025F − MAY 2001 − REVISED JULY 2002
APPLICATION INFORMATION
RSNS
0.2
Ω
DC+
C1
0.1
µF
R1
1 kΩ
bq2057
CC
SNS
VCC
C2
0.1
µF
GND
R2
2 kΩ
VSS
COMP
BAT
TS
STAT
D1
RT2
Battery
Pack
RT1
TEMP
VCC
PACK−
NTC
VCC
Q1
FZT788B
PACK+
Figure 1. Low Dropout Single- or Two-Cell Li-Ion/Li-Pol Charger
functional description
The bq2057 is an advanced linear charge controller for single or two-cell Li-Ion or Li-Pol applications. Figure 1
shows the schematic of charger using a PNP pass transistor. Figure 2 is an operational state diagram, and
Figure 3 is a typical charge profile. Figure 4 shows the schematic of a charger using P-channel MOSFET.
www.ti.com
7