beautypg.com

Rainbow Electronics BU4538B User Manual

Dual precision monostable multivibrator, Bu4538b, Standard ics

background image

1

Standard ICs

Dual precision monostable
multivibrator

BU4538B

The BU4538B is a monostable multivibrator that can be reset and retriggered. It is triggered from either edge of an

input pulse. As the output pulse width and accuracy are determined by the external timing constants Cx and Rx, a

wide range of accurate output pulse widths is available. Linear CMOS technology makes it possible to control the

output pulse width with greater accuracy. Determination is made based on t

WOUT

= Rx · Cx throughout the entire

power supply voltage range, eliminating the necessity for other coefficients.

Features

1) Low power dissipation.

2) Wide range of operating power supply voltages.

3) High input impedance.

4) High fan-out.

5) Direct drive of 2 L-TTL inputs and 1 LS-TTL input.

Block diagram

Logic circuit diagram

2

T

2A

T

1A

A

A

B

A

Q

A

Q

C

D

T

1

T

2

Q

Q

A

C

DA

3

4

5

6

7

8

15

14

13

12

11

10

9

V

SS

1

T

1B

V

DD

C

DB

A

B

B

B

Q

B

T

2B

Q

B

16

BA

Q

C

D

T

1

T

2

Q

BA

V

DD

R

X

2 (14)

1 (15)

4 (12)

T

1

V

ref1

E

nable

S

R

V

ref2

Reset Latch

Q

Q

E

nable

A

B

C

X

V

DD

Control

Output

Latch

Q

S

Q

R

T

2

C

D

5 (11)

3 (13)

6 (10)

7 (9)

Truth table

INPUT

OUTPUT

A

B

C

D

Q

Q

H

H

L

H

L

H

H

L

H

L

H

X

X

L

L

H

H