BQ29200 Datasheet, PDF (5/15 Pages) Texas Instruments – Voltage Protection with Automatic Cell Balance for 2-Series Cell Li-Ion Batteries

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bq29200
bq29209
SLUSA52 – JUNE 2010
ELECTRICAL CHARACTERISTICS (continued)
Typical values stated where T_A = 25°C and VDD = 7.2 V.
Min/Max values stated where T_A = –40°C to 110°C and VDD = 4 V to 10 V (unless otherwise noted).
PARAMETER
TEST CONDITION
MIN NOM MAX
V_{MM_DET_OFF}
Cell mismatch detection
threshold for turning
OFF
Delta between (VC2–VC1) and (VC1–GND) when cell
balancing is disabled V_DD = VC2 = 7.6 V
–9
0
9
V_{CB_EN_ON}
Cell balance enable ON
threshold
Active LOW pin at CB_EN
1
V_{CB_EN_OFF}
Cell balance enable
OFF threshold
Active HIGH at CB_EN
2.2
I_{CB_EN}
Cell balance enable ON
input current
CB_EN = GND (See Figure 2)
0.2
UNIT
mV
V
V
µA
RECOMMENDED CELL BALANCING CONFIGURATIONS
Typical values stated where T_A = 25°C and (VC2–VC1), (VC1–GND) = 3.8 V. Min/Max values stated where T_A = –40°C to
110°C, VDD = 4V to 10V, and (VC2–VC1), (VC1–GND) = 3.0 V to 4.2 V. All values assume recommended supply voltage
filter resistance R_VDD) of 100 Ω and 5% accurate or better cell balance resistor R_CB).
PARAMETER
TEST CONDITION
MIN NOM MAX UNIT
I_CB
Cell balance input current
R_CB = 4700 Ω
R_CB = 2200 Ω
R_CB = 910 Ω
R_CB = 560 Ω
R_CB = 360 Ω
R_CB = 240 Ω
R_CB = 120 Ω
0.5 0.75
1 1.5
2
3
3 4.5
3.5
6
4 7.5
5 10
1
2
4
6 mA
8.5
11
15
The cell balancing current may be calculated as follows:
Cell 1 (VC1–GND):
I_CB1
=
VC1
R_CB
Cell 2 (VC2–VC1):
I_CB2
=
(VC2 -
(R_CB +
VC1)
R_VB
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