BQ25703A Datasheet, PDF (27/81 Pages) Texas Instruments – I2C Multi-Chemistry Battery Buck-Boost Charge Controller With System Power Monitor and Processor Hot Monitor

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bq25703A
SLUSCU1 – MAY 2017
Voltage v V_SYS
Voltage v (V_SRN ± V_SRP)
CMPIN
1.2 V
Independent
Comparator
PROCHOT
bq2570x
Copyright © 2017, Texas Instruments Incorporated
Figure 14. PROCHOT Low Power Mode Implementation
8.3.8.2 PROCHOT Status
REG0x22[6:0] reports which event in the profile triggers PROCHOT by setting the corresponding bit to 1. The
status bit can be reset back to 0 after it is read by host, and current PROCHOT event is no longer active.
Assume there are two PROCHOT events, event A and event B. Event A triggers PROCHOT first, but event B is
also active. Both status bits will be HIGH. At the end of the 10 ms PROCHOT pulse, if PROCHOT is still active
(either by A or B), the PROCHOT pulse is extended.
8.3.9 Device Protection
8.3.9.1 Watchdog Timer
The charger includes watchdog timer to terminate charging if the charger does not receive a write
MaxChargeVoltage() or write ChargeCurrent() command within 175 s (adjustable via REG0x01[6:5]). When
watchdog timeout occurs, all register values are kept unchanged except ChargeCurrent() resets to zero. Battery
charging is suspended. Write MaxChargeVoltage() or write ChargeCurrent() commands must be re-sent to reset
watchdog timer and resume charging. Writing REG0x01[6:5] = 00 to disable watchdog timer also resumes
charging.
8.3.9.2 Input Overvoltage Protection (ACOV)
The charger has fixed ACOV voltage. When VBUS pin voltage is higher than ACOV, it is considered as adapter
over voltage. CHRG_OK will be pulled low, and converter will be disabled. As system falls below battery voltage,
BATFET will be turned on. When VBUS pin voltage falls below ACOV, it is considered as adapter voltage returns
back to normal voltage. CHRG_OK is pulled high by external pull up resistor. The converter resumes if enable
conditions are valid.
8.3.9.3 Input Overcurrent Protection (ACOC)
If the input current exceeds the 1.25× or 2× (REG0x32[2]) of I_LIM2_VTH (REG0x37[7:3]) set point, converter stops
switching. After 300 ms, converter starts switching again.
Copyright © 2017, Texas Instruments Incorporated
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