Datasheet

DRV
COLD
V
1
V
RHI =
1 1
+
RLO RCOLD
-
DRV
COLD HOT
DRV DRV
HOT COLD
1 1
V RCOLD RHOT
V V
RLO =
V V
RHOT 1 RCOLD 1
V V
é ù
´ ´ ´ -
ê ú
ë û
é ù é ù
´ - - ´ -
ê ú ê ú
ë û ë û
Portion of spec not covered by TS
0.5°C
1°C
4.25 V
4.15 V
4.1 V
T1
(0°C)
T2
(10°C)
T3
(45°C)
T4
(50°C)
T5
(60°C)
Implementation on bq24160
bq24160, bq24160A
bq24161, bq24161B
bq24163, bq24168
SLUSAO0E –NOVEMBER 2011–REVISED NOVEMBER 2013 www.ti.com
External NTC Monitoring (TS)
The I
2
C interface allows the user to easily implement the JEITA standard for systems where the battery pack
thermistor is monitored by the host. Additionally, the bq2416x provides a flexible, voltage based TS input for
monitoring the battery pack NTC thermistor. The voltage at TS is monitored to determine that the battery is at a
safe temperature during charging. The bq24160, bq24160A, bq24161B, bq24163, and bq24168 enable the user
to easily implement the JEITA standard for charging temperature while the bq24161 only monitors the hot and
cold cutoff temperatures and leaves the JEITA control to the host. The JEITA specification is shown in.
Figure 25. 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. Charging is suspended and timers are suspended when V
TS
< V
HOT
or V
TS
> V
COLD
. When V
WARM
>
V
TS
> V
HOT
, the battery regulation voltage is reduced by 140mV from the programmed regulation threshold.
When V
COLD
> V
TS
> V
COOL
, the charging current is reduced to half of the programmed charge current.
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 31. The resistor values are
calculated using the following equations:
(1)
(2)
Where:
V
COLD
= 0.60 × V
DRV
V
HOT
= 0.30 × V
DRV
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