54AC157.pdf

July 1998

54AC157 • 54ACT157

Quad 2-Input Multiplexer

General Description

The ’AC/’ACT157 is a high-speed quad 2-input multiplexer.

Four bits of data from two sources can be selected using the

common Select and Enable inputs. The four outputs present

the selected data in the true (noninverted) form. The ’AC/

’ACT157 can also be used as a function generator.

Features

n I CC and I OZ reduced by 50%

n Outputs source/sink 24 mA

n ’ACT157 has TTL-compatible inputs

n Standard Microcircuit Drawing (SMD)

— ’AC157: 5962-89539

— ’ACT157: 5962-89688

Logic Symbols

IEEE/IEC

DS100272-1

DS100272-2

Pin Names

Description

I 0a –I 0d

Source 0 Data Inputs

I 1 a –I 1d

Source 1 Data Inputs

Enable Input

Select Input

Z a –Z d

Outputs

Connection Diagrams

Pin Assignment

for DIP and Flatpak

Pin Assignment

for LCC

DS100272-3

DS100272-4

FACT ™ is a trademark of Fairchild Semiconductor Corporation.

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DS100272

Functional Description

The ’AC/’ACT157 is a quad 2-input multiplexer. It selects

four bits of data from two sources under th e control of a com-

mon S e lect input (S). The Enable input (E) is active-LOW.

When E is HIGH, all of the outputs (Z) are forced LOW re-

gardless of all other inputs. The ’AC/’ACT157 is the logic

implementation of a 4-pole, 2-position switch where the posi-

tion of the switch is determined by the logic levels supplied to

the Select input. The logic equations for the outputs are

shown below:

Z a = E • (I 1a • S+I 0a • S)

Z b = E • (I 1b • S+I 0b • S)

Z c = E • (I 1c • S+I 0c • S)

Z d = E • (I 1d • S+I 0d • S)

A common use of the ’AC/ACT157 is the moving of data from

two groups of registers to four common output busses. The

particular register from which the data comes is determined

by the state of the Select input. A less obvious use is as a

function generator. The ’AC/’ACT157 can generate any four

of the sixteen different functions of two variables with one

variable common. This is useful for implementing gating

functions.

Truth Table

Inputs

Outputs

I 0

I 1

H = HIGH Voltage Level

L = LOW Voltage Level

X = Immaterial

Logic Diagram

DS100272-5

Please note that this diagram is provided only for the understanding of logic operations and should not be used to estimate propagation delays.

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Absolute Maximum Ratings (Note 1)

If Military/Aerospace specified devices are required,

please contact the National Semiconductor Sales Office/

Distributors for availability and specifications.

Supply Voltage (V CC )

Recommended Operating

Conditions

Supply Voltage (V CC )

’AC

2.0V to 6.0V

−0.5V to +7.0V

’ACT

4.5V to 5.5V

DC Input Diode Current (I IK )

V I = −0.5V

Input Voltage (V I )

0VtoV CC

−20 mA

Output Voltage (V O )

0VtoV CC

V I = V CC + 0.5V

+20 mA

Operating Temperature (T A )

54AC/ACT

DC Input Voltage (V I )

−0.5V to V CC + 0.5V

−55˚C to +125˚C

DC Output Diode Current (I OK )

V O = −0.5V

Minimum Input Edge Rate (

−20 mA

’AC Devices

V IN from 30% to 70% of V CC

V CC @ 3.3V, 4.5V, 5.5V

V O = V CC + 0.5V

+20 mA

DC Output Voltage (V O )

−0.5V to V CC + 0.5V

125 mV/ns

DC Output Source

or Sink Current (I O )

Minimum Input Edge Rate (

± 50 mA

’ACT Devices

V IN from 0.8V to 2.0V

V CC @ 4.5V, 5.5V 125 mV/ns

Note 1: Absolute maximum ratings are those values beyond which damage

to the device may occur. The databook specifications should be met, without

exception, to ensure that the system design is reliable over its power supply,

temperature, and output/input loading variables. National does not recom-

mend operation of FACT ™ circuits outside databook specifications.

DC Characteristics for ’AC Family Devices

54AC

DC V CC or Ground Current

per Output Pin (I CC or I GND )

± 50 mA

Storage Temperature (T STG )

−65˚C to +150˚C

Junction Temperature (T J )

CDIP

175˚C

T A =

Symbol

Parameter

V CC

Units

Conditions

(V)

−55˚C to +125˚C

Guaranteed Limits

V OUT = 0.1V

V IH

Minimum High Level

3.0

2.1

Input Voltage

4.5

3.15

or V CC − 0.1V

5.5

3.85

V OUT = 0.1V

V IL

Maximum Low Level

3.0

0.9

Input Voltage

4.5

1.35

or V CC − 0.1V

5.5

1.65

I OUT = −50 µA

V OH

Minimum High Level

3.0

2.9

Output Voltage

4.5

4.4

5.5

5.4

(Note 2)

V IN = V IL or V IH

I OH = −12 mA

3.0

2.4

I OH = −24 mA

4.5

3.7

I OH = −24 mA

5.5

4.7

I OUT = 50 µA

V OL

Maximum Low Level

3.0

0.1

Output Voltage

4.5

0.1

5.5

0.1

(Note 2)

V IN = V IL or V IH

I OL = 12 mA

3.0

0.50

I OL = 24 mA

4.5

0.50

I OL = 24 mA

5.5

0.50

± 1.0

V I = V CC , GND

I IN

Maximum Input

5.5

µA

Leakage Current

V OLD = 1.65V Max

I OLD

Minimum Dynamic

Output Current (Note 3)

5.5

V OHD = 3.85V Min

I OHD

5.5

−50

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DC Characteristics for ’AC Family Devices (Continued)

54AC

T A =

Symbol

Parameter

V CC

Units

Conditions

(V)

−55˚C to +125˚C

Guaranteed Limits

V IN = V CC

I CC

Maximum Quiescent

5.5

80.0

µA

Supply Current

or GND

Note 2: All outputs loaded; thresholds on input associated with output under test.

Note 3: Maximum test duration 2.0 ms, one output loaded at a time.

Note 4: I IN and I CC @ 3.0V are guaranteed to be less than or equal to the respective limit @ 5.5V V CC .

I CC for 54AC @ 25˚C is identical to 74AC @ 25˚C.

DC Characteristics for ’ACT Family Devices

54ACT

T A =

Symbol

Parameter

V CC

Units

Conditions

(V)

−55˚C to +125˚C

Guaranteed Limits

V IH

Minimum High Level

4.5

2.0

V OUT = 0.1V

Input Voltage

5.5

2.0

or V CC − 0.1V

V IL

Maximum Low Level

4.5

0.8

V OUT = 0.1V

Input Voltage

5.5

0.8

or V CC − 0.1V

V OH

Minimum High Level

4.5

4.4

I OUT = −50 µA

Output Voltage

5.5

5.4

(Note 5)

V IN = V IL or V IH

I OH = −24 mA

4.5

3.70

I OH = −24 mA

5.5

4.70

I OUT = 50 µA

V OL

Maximum Low Level

4.5

0.1

Output Voltage

5.5

0.1

(Note 5)

V IN = V IL or V IH

I OL = 24 mA

4.5

0.50

I OL = 24 mA

5.5

0.50

± 1.0

V I = V CC , GND

I IN

Maximum Input

5.5

µA

Leakage Current

V I = V CC − 2.1V

I CCT

Maximum

5.5

1.6

I CC /Input

V OLD = 1.65V Max

I OLD

Minimum Dynamic

5.5

V OHD = 3.85V Min

I OHD

Output Current (Note 6)

5.5

−50

V IN = V CC

I CC

Maximum Quiescent

5.5

80.0

µA

Supply Current

or GND

Note 5: All outputs loaded; thresholds on input associated with output under test.

Note 6: Maximum test duration 2.0 ms, one output loaded at a time.

Note 7: I CC for 54ACT @ 25˚C is identical to 74ACT @ 25˚C.

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AC Electrical Characteristics

54AC

T A = −55˚C

V CC

Symbol

Parameter

(V)

to +125˚C

Units

C L = 50 pF

(Note 8)

Min

Max

t PLH

Propagation Delay

3.3

1.0

16.0

StoZ n

5.0

1.0

12.0

t PHL

Propagation Delay

3.3

1.0

14.0

StoZ n

5.0

1.0

11.5

t PLH

P ropagation Delay

3.3

1.0

16.0

EtoZ n

5.0

1.0

12.0

t PHL

P ropagation Delay

3.3

1.0

14.0

EtoZ n

5.0

1.0

11.5

t PLH

Propagation Delay

3.3

1.0

11.0

I n to Z n

5.0

1.0

9.0

t PHL

Propagation Delay

3.3

1.0

11.0

I n to Z n

5.0

1.0

9.0

Note 8: Voltage Range 3.3 is 3.3V ± 0.3V

Voltage Range 5.0 is 5.0V ± 0.5V

AC Electrical Characteristics

54ACT

V CC

T A = −55˚C

Symbol

Parameter

(V)

to +125˚C

Units

(Note 9)

C L = 50 pF

Min

Max

t PLH

Propagation Delay

5.0

1.0

11.5

StoZ n

t PHL

Propagation Delay

5.0

1.0

11.5

StoZ n

t PLH

P ropagation Delay

5.0

1.0

12.0

EtoZ n

t PHL

P ropagation Delay

5.0

1.0

10.0

EtoZ n

t PLH

Propagation Delay

5.0

1.0

8.5

I n to Z n

t PHL

Propagation Delay

5.0

1.0

9.0

I n to Z n

Note 9: Voltage Range 5.0 is 5.0V ± 0.5V

Capacitance

Symbol

Parameter

Typ

Units

Conditions

V CC = OPEN

C IN

Input Capacitance

4.5

V CC = 5.0V

C PD

Power Dissipation

50.0

Capacitance

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