17

ICS1722

Figure 9: Functional Diagram

+ 5 V

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

ICS1722

CHG

DCHG

PFN

MMN

CMN

SEL0

VSS

SEL1

MRN

RC

AUX0

AUX1

OPREF

VIN

VDD

CONSTANT

CURRENT

SOURCE

V

in

+ 5 V (note 5)

4.7µF

.047µF

.047µF

open

@ 45°C

R1

R2

R4 (note 1)

100pF

16k

Q1 (note 2)

1k

(note 3)

390

FAULT

MAINT

CHG

Notes:

1) Value of R4 determined by discharge current and capacity of battery pack.

2) Discharge FET is logic-level compatible in this application.

3) DC return of discharge FET must be connected close to negative battery terminal.

4) Regulated supply

5) Power ground; others are signal ground. Connect signal ground to power ground

at negative battery terminal only.

(note 6)

unused

+ 5 V

+ 5 V

390

R3

+ 5 V