17

ICS1700A

Figure 12: Functional Diagram

+ 5 V

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

ICS1700A

CHG

DCHG

PFN

CMN

OTN

SEL0

VSS

AVSS

SEL1

MRN

RC

THERM

VREF

VIN

VDD

CONSTANT

CURRENT

SOURCE

Vin

+ 5 V (note 5)

4.7µF

.047µF

.047µF

10k

@ 25°C

open

@ 45°C

+ 5 V

R1

R2

R3 (note 1)

27k (note 4)

100pF

16k

Q1 (note 2)

1k

(note 3)

390

FAULT

CHG

TEMP

Ω

Notes:

1) Value of R3 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) Resistor is needed only if a thermistor is used. Value may change depending on thermistor.

5) Regulated supply

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

at negative battery terminal only.

(note 6)

temperature

sense

options

unused

+ 5 V

+ 5 V

390