BQ24004 Datasheet, PDF (15/22 Pages) Texas Instruments – TWO-CELL Li-ION CHARGE MANAGEMENT IC FOR PDAs AND INTERNET APPLIANCES

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V_CC
Temp Fault
V_TP1
Normal Temp Range
V_TP2
Temp Fault
GND
bq24004
bq24005
bq24006
SLUS476B – DECEMBER 2000 – REVISED MAY 2002
VCC
DC+
R1
R2
DC–
U1
1
N/C
20
N/C
2
IN
19
OUT
3
IN
18
OUT
4
VCC
17
VSENSE
5
ISNS
16
AGND
6
N/C
15
STAT2
7
14
APG/THM STAT1
8 _EN
TMR SEL ¹³
9 _VSEL
CR ¹²
10 _GND
N/C ¹¹
bq24005PWP
Figure 17. Temperature Threshold
Figure 18. APG Sensing Circuit
Values of resistors R1 and R2 can be calculated using the following equation:
V_(APG)
+
V_CC
R2
(R1 ) R2)
where V_(APG) is the voltage at the APG/THM pin.
Current Regulation
The bq2400x provides current regulation while the battery-pack voltage is less than the regulation voltage. The current
regulation loop effectively amplifies the error between a reference signal, Vilim, and the drop across the external sense
resistor, R_SNS.
VCC
U1
DC+
R(SNS)
C1
10 µF +
VCC
1
N/C
2
IN
3 _IN
20
N/C
19
OUT
OUT ¹⁸
DC–
4 _VCC
5 _ISNS
VSENSE ¹⁷
AGND ¹⁶
C2
0.1 µF
6
N/C
7
APG/THM
15
STAT2
14
STAT1
8
EN
13
TMR SEL
9
VSEL
12
CR
10
GND
11
N/C
bq24005PWP
Figure 19. Current Sensing Circuit
15