SMBus Level 2 Battery Charger
with Remote Sense
command. The charge current-regulation loop is in con-
the set point. A third loop (CCS) takes control and
reduces the charge current when the adapter current
exceeds the input current limit set by the InputCurrent()
command.
trol as long as the selected battery voltage is below the
charge voltage set point. When the selected battery
voltage reaches its set point, the voltage-regulation
loop takes control and maintains the battery voltage at
A functional diagram is shown in Figure 2.
2V
150mV
(10A FOR RS2 = 10mΩ)
(750mA FOR RS2 = 10mΩ)
MAX8731A
BST
DHI
CSSP
CSIN
POWER-FAIL
IMAX
ZCMP
ENABLE
IMIN
HIGH-
SIDE
DRIVER
100mV
ACIN
LX
LEVEL
SHIFT
VCC
DC-DC
ACOK
CONVERTER
LDO
LVC
LOW-
SIDE
CCMP
DLO
REF/2
GND
CCV
CCI
DRIVER
OVP
PGND
LOWEST VOLTAGE CLAMP
5.4V
LINEAR
REGULATOR
GMV
DCIN
V
CC
GMI
+
200mV
-
4.096V
REFERENCE
CCS
REF
CSI
CSA: CURRENT-SENSE
AMPLIFIER
SMBus LOGIC
GMS
SCL
SDA
11-BIT DAC
6-BIT DAC
6-BIT DAC
CHARGE VOLTAGE ( )
A = 1V/V
CSA
CSS
CHARGE CURRENT ( )
INPUT CURRENT ( )
A = 20V/V
V
DD
GM
CSA
A = 20V/V
Figure 2. Functional Diagram
______________________________________________________________________________________ 15
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
