BQ24193_15 Datasheet, PDF (21/49 Pages) Texas Instruments – bq24193 I2C Controlled 4.5-A Single Cell USB/Adapter Charger with Narrow VDC Power Path Management and USB OTG

bq24193
www.ti.com
SLUSBG7 – DECEMBER 2014
8.3.4.2 Charging Status Indicator (STAT)
The bq24193 indicates charging state on the open drain STAT pin. The STAT pin can drive LED as the
application diagram shows.
Table 5. STAT Pin State
CHARGING STATE
Charging in progress (including recharge)
Charging complete
Sleep mode, charge disable
Charge suspend (Input over-voltage, TS fault, timer fault, input or system over-
voltage)
STAT
LOW
HIGH
HIGH
blinking at 1Hz
8.3.4.3 Interrupt to Host (INT)
In some applications, the host does not always monitor the charger operation. The INT notifies the system on the
device operation. The following events will generate 256-us INT pulse.
• USB/adapter source identified (through PSEL and OTG pins)
• Good input source detected
– V_VBUS - V_BAT > V_SLEEPZ
– V_VBUS > V_ACOV
– current limit above I_BADSRC
• Input removed
• Charge Complete
• Any FAULT event in REG09
When a fault occurs, the charger device sends out INT and keeps the fault state in REG09 until the host reads
the fault register. Before the host reads REG09 and all the faults are cleared, the charger device would not send
any INT upon new faults. In order to read the current fault status, the host has to read REG09 two times
consecutively. The 1^st reads fault register status from the last read and the 2^nd reads the current fault register
status.
8.3.5 Protections
8.3.5.1 Input Current Limit on ILIM
For safe operation, the bq24193 has an additional hardware pin on ILIM to limit maximum input current on ILIM
pin. The input maximum current is set by a resistor from ILIM pin to ground as:
1V
I_INMAX = _RILIM ´ 530
(3)
The actual input current limit is the lower value between ILIM setting and register setting (REG00[2:0]). For
example, if the register setting is 111 for 3 A, and ILIM has a 353-Ω resistor to ground for 1.5 A, the input current
limit is 1.5 A. ILIM pin can be used to set the input current limit rather than the register settings.
The device regulates ILIM pin at 1 V. If ILIM voltage exceeds 1 V, the device enters input current regulation
(Refer to Dynamic Power Path Management section).
The voltage on the ILIM pin is proportional to the input current. The ILIM pin can be used to monitor the input
current per Equation 4:
IIN
=
V_ILIM
1V
´ I_INMAX
(4)
For example, if the ILIM pin sets 2 A, and the ILIM voltage is 0.6 V, the actual input current is 1.2 A. If the ILIM
pin is open, the input current is limited to zero since ILIM voltage floats above 1 V. If the ILIM pin is short, the
input current limit is set by the register.
Copyright © 2014, Texas Instruments Incorporated
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