MAX1645B Datasheet, PDF (22/32 Pages) Maxim Integrated Products – Advanced Chemistry-Independent, Level 2 Battery Charger with Input Current Limiting

Advanced Chemistry-Independent, Level 2
Battery Charger with Input Current Limiting
18.432V
16.800V
V_REF = 4.096V
VDCIN > 20V
12.592V
8.400V
4.192V
1.024V
0
0
0x0400
0x106x
0x20Dx
0x313x
ChargingVoltage() D15–D0 DATA
Figure 7. ChargingVoltage() Code to Voltage Mapping
0x41A0 0x4800
0xFFFF
(the voltage-regulation-loop set point) and the
ChargingVoltage() code.
The power-on reset value for the ChargingVoltage() reg-
ister is 0x4880; thus, the first time a MAX1645B is pow-
ered on, the BATT voltage regulates to 18.432V. Any
time the battery is removed, the ChargingVoltage() reg-
ister returns to its power-on reset state. The voltage at
DAC corresponds to the set compliance voltage divided
by 4.5.
AlarmWarning() (POR: Not Alarm)
The AlarmWarning() command uses the write-word
protocol (Figure 3a). The command code for
AlarmWarning() is 0x16 (0b00010110). AlarmWarning()
sets the ALARM_INHIBITED status bit in the MAX1645B
if D15, D14, D13, D12, or D11 of the write-word protocol
data equals 1. Table 6 summarizes the Alarm-Warning()
command’s function. The ALARM_INHIBITED status bit
remains set until the battery is removed, a
ChargerMode() command is written with the
POR_RESET bit set, or new ChargingCurrent() AND
ChargingVoltage() values are written. As long as
ALARM_INHIBITED = 1, the MAX1645B switching regu-
lators remain off.
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