BQ24266_15 Datasheet, PDF (21/41 Pages) Texas Instruments – bq24266 3A, 30V Standalone Single-Input, Single-Cell Switchmode Li-Ion Battery Charger

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bq24266
SLUSBY5F – JUNE 2014 – REVISED AUGUST 2015
Device Functional Modes (continued)
Table 1. IUSB1, IUSB2, and IUSB3 Configurations
IUSB3
0
0
0
0
1
1
1
1
IUSB2
0
0
1
1
0
0
1
1
IUSB1
0
1
0
1
0
1
0
1
MODE
Charger
Charger
Charger
Boost
Charger
Charger
Charger
High Impedance
INPUT CURRENT
LIMIT
100mA
500mA
1.5A
---
150mA
900mA
2500mA
---
VINDPM
THRESHOLD
4.28V
4.44V
External
---
4.28V
4.44V
External
---
7.4.11 Safety Timer in Charge Mode
At the beginning of the charging process, the bq24266 starts the safety timer. This timer is active during the
entire charging process. If charging has not terminated before the safety timer expires, the IC enters suspend
mode where charging is disabled. CE, or power must be toggled in order to clear the safety timer fault. The
bq24266 also contains a 2X_TIMER that doubles the safety timer to prevent premature safety timer expiration
when the charge current is reduced by a load on SYS or a NTC condition. When 2X_TIMER is active, the timer
runs at half speed when any loop is active other than CC or CV. This includes V_INDPM, input current limit, or
thermal regulation. The timer also runs at half speed during TS warm/cool conditions.
7.4.12 LDO Output (DRV)
The bq24266 contains a linear regulator (DRV) that is used to supply the internal MOSFET drivers and other
circuitry. Additionally, DRV supplies up to 10mA external loads to power the PG or CHG LED or the USB
transceiver circuitry. The maximum value of the DRV output is 5.3V so it ideal to protect voltage sensitive USB
circuits. The LDO is on whenever a supply is connected to the input of the bq24266. The DRV is disabled under
the following conditions:
1. V_SUPPLY < UVLO
2. V_SUPPLY < V_BAT + V_SLP
3. Thermal Shutdown
7.4.13 External NTC Monitoring (TS)
The bq24266 provides a flexible, voltage based TS input for monitoring the battery pack NTC thermistor. The
bq24266 implements the full JEITA standard. The voltage at TS is monitored to determine that the battery is at a
safe temperature during charging. The JEITA specification is shown in Figure 12.
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