National Semiconductor 54122, DM74122 Technical data

54122/DM74122
Retriggerable Resettable Multivibrator

General Description

The ’122 features positive and negative DC level triggering
inputs, complementary outputs, an optional 10 kX internal
timing resistor and an overriding Direct Clear (C
When the circuit is in the quasi-stable (delay) state, another

) input.

D

trigger applied to the inputs (per Truth Table) will cause the
delay period to start again, without disturbing the outputs.
This process can be repeated indefinitely and thus the out­put pulse period (Q HIGH, Q

LOW) can be made as long as

desired. Alternatively, a delay period can be terminated

by a LOW signal applied to C
ing. An internal connection from C
it possible to trigger the circuit by a positive-going signal on
C

, as shown in the Truth Table. For timing capacitor values

D

greater than 1000 pF, the output pulse width is defined as
follows:

t

w

Where twis in ns, RXis in kX and CXis in pF.

, which also prevents trigger-

D

to the input gate makes

D

e

0.32 RXCX(1.0a0.7/RX)

54122/DM74122 Retriggerable Resettable Multivibrator

June 1989

Connection Diagram

Dual-In-Line Package

Order Number 54122DMQB, 54122FMQB or DM74122N

See NS Package Number J14A, N14A or W14B

Pin Names Description

A1,A
B

1,B2

C

D

Q, Q

TL/F/10212– 1

2

Trigger Inputs (Active Falling Edge)
Trigger Inputs (Active Rising Edge)
Direct Clear Inputs (Active LOW)
Outputs

Logic Symbol

V

CC

GND
NC

e

e

Pin 14

e

Pin 7

Pins 10 and 12

TL/F/10212– 2

C

1995 National Semiconductor Corporation RRD-B30M105/Printed in U. S. A.

TL/F/10212

Absolute Maximum Ratings (Note)

If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales
Office/Distributors for availability and specifications.

Supply Voltage 7V

Input Voltage 5.5V

Operating Free Air Temperature Range

54
DM74 0

Storage Temperature Range

b

55§Ctoa125§C

Ctoa70§C

§

b

65§Ctoa150§C

Recommended Operating Conditions

Symbol Parameter

V

CC

V

IH

V

IL

I

OH

I

OL

T

A

Supply Voltage 4.5 5 5.5 4.75 5 5.5 V

High Level Input Voltage 2 2 V

Low Level Input Voltage 0.8 0.8 V

High Level Output Current

Low Level Output Current 16 16 mA

Free Air Operating Temperature

Min Nom Max Min Nom Max

b

55 125

The ‘‘Absolute Maximum Ratings’’ are those values

Note:

beyond which the safety of the device cannot be guaran­teed. The device should not be operated at these limits. The
parametric values defined in the ‘‘Electrical Characteristics’’
table are not guaranteed at the absolute maximum ratings.
The ‘‘Recommended Operating Conditions’’ table will define
the conditions for actual device operation.

54122 DM74122

b

0.8

b

55 70

b

0.8 mA

Units

C

§

Recommended Operating Conditions V

CC

ea

Symbol Parameter Conditions

5.0V, T

A

ea

25§C

DM74

Units

Min Max

t

w

R

X

C

X

Trigger Pulse Width 40 ns

External Timing Resistor XC Over Operating VCCand 5.0 50

XM

Temperature Range

5.0 25

External Timing Capacitor No Restrictions pF

Electrical Characteristics over recommended operating free air temperature range (unless otherwise noted)

Symbol Parameter Conditions Min

e

e

Max

e

e

e

Min, I

Min, I

Min, V

Max, V

Max, V

eb

12 mA

I

e

Max,

OH

e

Min 0.4 V

IH

e

5.5V

I

e

2.4V Inputs 40

I

2.4 V

V

I

V

OH

V

OL

I

I

I

IH

Input Clamp Voltage V

High Level Output Voltage V

Low Level Output Voltage V

Input Current@Max V
Input Voltage

High Level Input Current V

CC

CC

e

V

IL

CC

CC

CC

Clear 80

I

IL

Low Level Input Current V

CC

e

Max, V

e

0.4V Inputs

I

Clear

I

OS

I

CC

Note 1: All typicals are at V

Note 2: Not more than one output should be shorted at a time, and the duration should not exceed one second.

Short Circuit Output Current V

Supply Current V

e

e

5V, T

CC

25§C.

A

e

Max (Note 2)

CC

e

Max 28 mA

CC

b

10

Typ

(Note 1)

Max Units

b

1.5 V

1mA

b

1.6

b

3.2

b

40 mA

kX

mA

mA

2