MAX1647 Datasheet, PDF (18/24 Pages) Maxim Integrated Products – Chemistry-Independent Battery Chargers

Chemistry-Independent
Battery Chargers
Figure 8 shows the mapping between V0 (the voltage-
regulation-loop set point) and the ChargingVoltage( )
data.
The power-on reset value for the ChargingVoltage( )
register is 0xFFF0; thus, the first time a MAX1647 is
powered on, the BATT voltage regulates to 16.368V
with V_REF = 4.096V. Any time the BATTERY_PRESENT
status bit is clear, the ChargingVoltage( ) register
returns to its power-on reset state.
ChargingCurrent( )
The ChargingCurrent( ) command uses Write-Word
protocol. The command code for ChargingCurrent( ) is
0x14; thus, the CMD7–CMD0 bits in Write-Word proto-
col should be 0b00010100. The 16-bit binary number
formed by D15–D0 represents the current-limit set point
(I0) in milliamps. Tying SEL to AGND selects a 1.023A
maximum setting for I0. Leaving SEL open selects a
2.047A maximum setting for I0. Tying SEL to VL selects
a 4.095A maximum setting for I0.
16.368
V_REF = 4.096V
12.592
8.400
4.192
0
0b000000000000xxxx
0x000x
0b000100000110xxxx
0x106x
0b001000001101xxxx
0x20Dx
0b001100010011xxxx 0b001111111111xxxx
0x313x
0x3FFx
0b111111111111xxxx
0xFFFx
ChargingVoltage( ) D15–D0 DATA
Figure 8. ChargingVoltage( ) Data to Voltage Mapping
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