NE556 参数 Datasheet PDF下载

NE556/SA556/SE556

TONE BURST GENERATOR

For a tone burst generator the first timer is used as a monostable and determines the tone duration when

triggered by a positive pulse at pin 6. The second timer is enabled by the high output os the monostable. It

is connected as an astable and determines the frequency of the tone.

Re s e t

4

Vcc

14

14

+15V

R

t

Trigge r

Trigge r

6

Discha rge

1

2

Thre s hold

C1

Ground

0.01

µ

F

1/2

NE556

S E556

Control

3

Output

11 C ontrol

9

Ground

0.01

µ

F

5

Output

10

Re s e t

1/2

NE556

S E556

Discha rge

13

R

A

R

B

12 Thre s hold

8 Trigge r

C2

Ground

T = 1.1 R

t

.C1

f=

1.44

R

A

+ 2R

B

) C

MONOSTABLE OPERATION

V

CC

R

L

4

Trigge r

(10)

6 (8)

ASTABLE OPERATION

V

CC

R

A

14

(13)

1

R

L

4

(10)

(13)

1

O utput

5 (9)

R

A

14

1/2

NE556

S E556

(12)

Output

5 (9)

7

R

L

(11)

3

10nF

2

1/2

NE556

S E556

(12)

R

B

R

L

7

(11)

3

(8)

6

2

C

0.01nF

1.44

f=

R

A

+ 2R

B

) C

C

Opera ting frequency

T = 1.1 R

A

.C

t

1

= 0.693 (R

A

+ R

B

) C Output High

t

2

= 0.693 R

B

C Output Low

t2

t1

7/9