2003/9/1

6

ES51963

4 1/2 DMM

buzzer frequency is determined by the following formula:

)

(

)

0

,

1

,

2

(

40

1

1

Hz

B

B

B

F

fosc

fbuz

　　

×

=

where,

fosc1 : ES51963 operating frequency.

fbuz : the frequency of BUZout.

B2, B1, B0 : control bits provided by external microprocessor.

F

According to the formula, a user can select a favorite buzzer frequency among the

audible frequency range. The values of B2, B1 and B0 are 0, 1 and 0 respectively in default.

The buzzer frequencies and the ratios determined by B2, B1 and B0 with various operating

frequencies are shown in the following table.

fbuz

B2 B1 B0

fosc1

F

6M

4M

2M

1.2M

1M

800k

600k

400k

1 1 1

3

50.00 33.33 16.67 10.00

8.33

6.67

5.00

3.33

1 1 0

5

30.00 20.00 10.00

6.00

5.00

4.00

3.00

2.00

1 0 1

9

16.67 11.11

5.56

3.33

2.78

2.22

1.67

1.11

1 0 0

15

10.00

6.67

3.33

2.00

1.67

1.33

1.00

0.67

0 1 1

30

5.00

3.33

1.67

1.00

0.83

0.67

0.50

0.33

0 1 0

50

3.00

2.00

1.00

0.60

0.50

0.40

0.30

0.20

0 0 1

90

1.67

1.11

0.56

0.33

0.28

0.22

0.17

0.11

0 0 0

150

1.00

0.67

0.33

0.20

0.17

0.13

0.10

0.07

Unit : fosc1 : Hz , fbuz : kHz

In this table the data with gray blocks are recommended frequency values. A user thus

can easily choose a buzzer frequency based on the table.

(3) Conversion Rate

The ES51963 provided several conversion rates (CRs) that can be selected by external

microprocessor. The way to change conversion rate is similar to that of buzzer frequency

selection. and the CRs follow the below formula:

sec)

/

(

10

4

)

0

,

1

,

2

(

1

6

2

times

C

C

C

F

fosc

CR

　　

×

×

=

where,

fosc1 : ES51963 operating frequency.

CR : conversion rate.

C2, C1, C0 : provided by external microprocessor.

F

According to the formula, a user can select a conformable and reasonable conversion rate.

The values of C2, C1 and C0 are 0, 1 and 1 respectively in default. Thus the default

conversion rate is 10 times/sec with 4 MHz operating frequency. The following table lists