Low-Cost, Multichemistry Battery-
Charger Building Block
MAX172
RS1
0.04Ω
TO EXTERNAL
LOAD
V
IN
8VDC TO 28VDC
D1
C1
C2
22μF
22μF
R14
R15
4.7Ω
4.7Ω
C6
O.47μF
C7
O.47μF
3.30V
1.5kΩ
D4
910Ω
3.30V
R6
CSSP
DCIN
CSSN
CELLS
59.0kΩ
R7
19.6kΩ
C5
1μF
R19
R21
LDO
29.4kΩ
10kΩ
C13
R13
33Ω
1μF
D3
REFIN
VCTL
R20
10kΩ
R22
10kΩ
BST
DLOV
C15
0.1μF
C16
1.0μF
ICTL
R8
1M
ACIN
ACOK
ICHG
N1
DHI
LX
N2
DLO
D2
MAX1772
L1
22μH
PGND
R11
1Ω
IINP
CCV
CSIP
C14
0.1μF
C20
0.1μF
R9
15.4kΩ
R10
12.4kΩ
C18
0.1μF
R5
RS2
0.05Ω
1kΩ
C11
0.1μF
R12
1Ω
C19
0.1μF
CSIN
BATT
GND
CCI
+
BATT
CCS
C9
0.01μF
C10
0.01μF
C3
22μF
C4
22μF
BATTERY
REF
CLS
BATT-
C12
1μF
Figure 1b. Stand-Alone Typical Application Circuit
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