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SS6783A(G)

1/11/2005 Rev.2.10

The functions and charging state control mentioned

above are illustrated in the function flow-chart of

the SS6

783A (Fig. 12)

DESIGN GUIDE

Battery Voltage Measurement

The SS6783A measures the battery voltage

through VBT pin, which is connected to the battery

positive terminal through a resistor-divider network,

as shown in Fig. 11.

RA

RB

C5

7

R5

100k

C6

SS6

783A

VBT

+

Fig. 11

Battery Voltage Divider

The suggested divider resistance of RA and RB

for the corresponding number of battery cells are

as below:

TABLE 1

BATTERY

CELLS

RA/RB

RA (k

Ω)

RB (k

Ω)

2~4

2

240

120

3~6

3.3

300

91

4~8

4.9

300

62

5~10

6.4

300

47

6~12

7.8

310

39

8~16

10.8

390

36

Setting the Period of Safety Timer

The SS6783A provides a method for linearly adjusting

the period of the safety timer with an external resistor

connected from TIMER pin to GND.

The

relation between safety timer length and the

table following shows the resistor values for some

of the commonly chosen safety timer periods. Also

shown in the table are their corresponding oscillator

frequencies.

0

100

200

300

400

500

0

200

400

600

800

Safety Timer (min.)

Fig. 13