Analog Devices LINEAR LT8491 Manual page 53

2
I C REGISTER DESCRIPTIONS
A specific use case for the CFG_RSTRT_IN_FLT register is when a dead battery needs to be replaced. The user may
want the charger to remain off until the battery is exchanged. A voltage measurement might be required prior to start-
ing the charger. Once the battery is verified, CTRL_CHRG_EN can be used to start the charging logic. Figure 9 shows a
sample setup for the CFG_RSTRT_IN_FLT register. The scenario displays what happens when the LT8491 is configured
to not restart when a low battery fault is detected. In time, the LT8491 first detects a LOW_VBAT_FLT, followed by a
BAT_DISCON_FLT due to the dead battery being disconnected from the charger. The fault indication is priority based
but the restart condition behaves unconditionally from the prioritized fault indication.
Related Data Sheet Sections: Charging Faults, Battery Charging Algorithm, CFG_TERMINATE, Configure Stage
Timeout Limits
RSTRT_ON_TMR_FLT_HRS [7:4] = 0000b
NO_RSTRT_ON_VOLTS [3] = 0
NO_RSTRT_ON_DISCON_FLT [2] = 0
NO_RSTRT_ON_BATLOW_FLT [1] = 1
NO_RESUME_ON_TBAT_FLT [0] = 0
LOW_VBAT_FLT
OCCURS
t t + 1
@ t STAT_CHRG_FAULTS = 0X00
@ t + 1 STAT_CHRG_FAULTS = 0X01 (NO RESTART IS SET)
@ t + 2 STAT_CHRG_FAULTS = 0X08 (HIGHEST PRIORITY FAULT THAT IS PRESENT IS INDICATED)
@ t + 3 STAT_CHRG_FAULTS = 0X00
@ t + 4 CTRL_CHRG_EN = 0
@ t + 5 CTRL_CHRG_EN = 1
CFG_RSTRT_IN_FLT = 0x02
BAT_DISCON_FLT BOTH FAULTS
OCCURS
t + 2
Figure 9. No Restart Condition Example
For more information
BATTERY REPLACEMENT
NO
CTRL_CHRG_EN
RESTART
CLEAR
t + 3
TIME (t)
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LT8491
NO
CTRL_CHRG_EN
RESTART
= 0 = 1
t + 4 t + 5
RESTART
8491 F09
Rev. 0
53