Low-Cost Multichemistry Battery Chargers

14

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TO EXTERNAL

LOAD

MAX1908

MAX8724

CLS

REF

GND

CELLS

REFIN (4 CELLS SELECT)

DLOV

AC ADAPTER

INPUT

8.5V TO 28V

DHI

D3

BST

BATTERY

ACIN

D2

LDO

LDO

16.8V OUTPUT VOLTAGE

2.5A CHARGE LIMIT

4A INPUT CURRENT LIMIT

R6

59k

Ω

1%

R7

19.6k

Ω

1%

R11

15k

Ω

R12

12k

Ω

C5

1

µF

C12

1.5nF

SHDN

ICHG

IINP

R19

10k

Ω

1%

R20

10k

Ω

1%

CCV

C11

0.1

µF

R5

1k

Ω

CCI

CCS

C10

0.01

µF

C9

0.01

µF

C12

1

µF

C1

2

× 10µF

C13

1

µF

C15

0.1

µF

LX

C16

1

µF

LDO

R13

33

Ω

CSSP

CSSN

RS1

0.01

Ω

L1

10

µH

RS2

0.015

Ω

CSIP

CSIN

PGND

DLO

N1b

N1a

FROM HOST

µP

(SHUTDOWN)

N

BATT

GND

PGND

C4

22

µF

BATT+

REFIN

VCTL

DCIN

BATT-

THM

ICTL

R14

10.5k

Ω

1%

R15

8.25k

Ω

1%

R16

8.25k

Ω

1%

P1

R17

19.1k

Ω

1%

R18

22k

Ω

1%

ACOK

0.01

µF 0.01µF

Figure 2. Typical Application Circuit with Fixed Charging Parameters

Typical Application Circuits (continued)