Max1870a step-up/step-down li+ battery charger – Rainbow Electronics MAX1870A User Manual
Page 17
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MAX1870A
Step-Up/Step-Down
Li+ Battery Charger
______________________________________________________________________________________
17
MAX1870A
CSSN
CSSP
CSSS
CLS
CCS
ICTL
CCI
CSIP
CSIN
CCV
BATT
CELLS
VCTL
A = 18V/V
A = 18V/V
CSS
CURRENT-
SENSE
AMPLIFIERS
3.6V
(6.7A FOR 30mΩ)
IMAX1
INPUT-CURRENT BLOCK
GMS
IINP
ASNS
Gm
0.81mV
(1.5A FOR 30mΩ)
50mV
REFIN
x
400mV
REFIN
x
GMI
A = 18V/V
CSI
22.5mV
(42mA ON
30mΩ)
(6.7A FOR 30mΩ)
3.6V
IZX
IMAX2
CHARGE-CURRENT BLOCK
+ 4.0V
4.2V
GMV
REF
CELL-
SELECT
LOGIC
BATTERY-VOLTAGE BLOCK
SHUTDOWN LOGIC
5.4V LINEAR
REGULATOR
4.096V
REFERENCE
DCIN
LDO
REF
REFIN
1/55
CHG
RDY
ICTL
23% OF
REFIN
GND
PGND
DLOV
VHN
DHI
VHP
DBST
SHDN
LEVEL
SHIFT
STEP-UP/DOWN
CURRENT-MODE
STATE MACHINE
IMAX1
LVC
IMIN
0.15V
LVC
LOW-
SIDE
DRIVER
HIGH-
SIDE
DRIVER
Figure 3. Functional Diagram
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