SMBus Level 2 Battery Charger
with Remote Sense
16mV resolution. Set ChargeVoltage() below 1.024V to
Setting Charge Voltage
To set the output voltage, use the SMBus to write a 16-bit
ChargeVoltage() command using the data format listed in
Table 1. The ChargeVoltage() command uses the Write-
Word protocol (see Figure 3). The command code for
ChargeVoltage() is 0x15 (0b00010101). The MAX8731A
provides a 1.024V to 19.200V charge voltage range, with
terminate charging. Upon reset, the ChargeVoltage() and
ChargeCurrent() values are cleared and the charger
remains off until both the ChargeVoltage() and the
ChargeCurrent() command are sent. Both DHI and DLO
remain low until the charger is restarted.
Table 1. ChargeVoltage () (0x15)
BIT
0
BIT NAME
DESCRIPTION
—
—
—
—
Not used. Normally a 1mV weight.
1
Not used. Normally a 2mV weight.
Not used. Normally a 4mV weight.
Not used. Normally a 8mV weight.
2
3
0 = Adds 0mV of charger voltage compliance, 1024mV min.
1 = Adds 16mV of charger voltage compliance.
4
5
Charge voltage, DACV 0
Charge voltage, DACV 1
Charge voltage, DACV 2
Charge voltage, DACV 3
Charge voltage, DACV 4
Charge voltage, DACV 5
Charge voltage, DACV 6
Charge voltage, DACV 7
Charge voltage, DACV 8
Charge voltage, DACV 9
0 = Adds 0mV of charger voltage compliance, 1024mV min.
1 = Adds 32mV of charger voltage compliance.
0 = Adds 0mV of charger voltage compliance, 1024mV min.
1 = Adds 64mV of charger voltage compliance.
6
0 = Adds 0mV of charger voltage compliance, 1024mV min.
1 = Adds 128mV of charger voltage compliance.
7
0 = Adds 0mV of charger voltage compliance, 1024mV min.
1 = Adds 256mV of charger voltage compliance.
8
0 = Adds 0mV of charger voltage compliance, 1024mV min.
1 = Adds 512mV of charger voltage compliance.
9
0 = Adds 0mA of charger voltage compliance.
1 = Adds 1024mV of charger voltage compliance.
10
11
12
13
0 = Adds 0mV of charger voltage compliance.
1 = Adds 2048mV of charger voltage compliance.
0 = Adds 0mV of charger voltage compliance.
1 = Adds 4096mV of charger voltage compliance.
0 = Adds 0mV of charger voltage compliance.
1 = Adds 8192mV of charger voltage compliance.
0 = Adds 0mV of charger voltage compliance.
1 = Adds 16,384mV of charger voltage compliance, 19,200mV max.
14
15
Charge voltage, DACV 10
—
Not used. Normally a 32,768mV weight.
16 ______________________________________________________________________________________
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
