BQ24266_15 Datasheet, PDF (22/41 Pages) Texas Instruments – bq24266 3A, 30V Standalone Single-Input, Single-Cell Switchmode Li-Ion Battery Charger

bq24266
SLUSBY5F – JUNE 2014 – REVISED AUGUST 2015
1.0 C
Charging Current 0.5 C
4.25 V
V_BAT 4.15 V
4.1 V
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Portion of spec not covered by TS
Implementation on bq2426x
T1
(0°C)
Cold
T2
(10°C)
Cool
T3 T4
(45°C) (50°C)
Warm
T5
(60°C)
Hot
Figure 12. Charge Current During TS Conditions
To satisfy the JEITA requirements, four temperature thresholds are monitored; the cold battery threshold (T_NTC <
0°C), the cool battery threshold (0°C < T_NTC < 10°C), the warm battery threshold (45°C < T_NTC < 60°C) and the
hot battery threshold (T_NTC > 60°C). These temperatures correspond to the V_COLD, V_COOL, V_WARM, and V_HOT
thresholds in the EC table. Charging is suspended and timers are suspended when V_TS < V_HOT or V_TS > V_COLD.
When V_COOL < V_TS < V_COLD, the charging current is reduced to half of the programmed charge current. When
V_HOT < V_TS < V_WARM, the battery regulation voltage is reduced to 4.06V from the 4.2V regulation threshold. The
TS function is disabled by connecting TS directly to DRV (V_TS > V_TSOFF).
The TS function is voltage based for maximum flexibility. Connect a resistor divider from DRV to GND with TS
connected to the center tap to set the threshold. The connections are shown in Figure 13. The resistor values are
calculated using the following equations:
RLO =
V_DRV
´ RCOLD
´ RHOT
´
é
ê
ë
1
V_COLD
-
1^ù
ú
V_{HOT û}
RHOT
´
é
ê
V_DRV
ù
é
- 1_ú - RCOLD ´ _ê
VDRV
ù
- 1_ú
ë ^VHOT û
ë ^VCOLD û
(3)
RHI =
V_{DRV - 1}
V_COLD
1
1
+
RLO RCOLD
(4)
Where:
V_COLD = 0.60 × V_DRV
V_HOT = 0.30 × V_DRV
RCOOL
=
RLO
-
RLO ´ RHI´
RLO ´ 0.564
0.564
- RHI´
0.564
(5)
22
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