MC74LCX258

http://onsemi.com

2

Figure 1. Pinout: 16−Lead Plastic Package

(Top View)

15

16

14

13

12

11

10

2

1

3456

7

9

8

OE

A3

B3

Y3

A2

B2

Y2

S

A0

B0

Y0

A1

B1

Y1

GND

PIN NAMES

Pins

Function

An

Source 0 Data Inputs

Bn

Source B Data Inputs

OE

Enable Input

S

Select Input

Yn

Outputs

TRUTH TABLE

Inputs

Outputs

Output Enable

Select

Y0−Y3

H

X

Z

L

L

A0−A3

L

H

B0−B3

X = Don’t Care

A0−A3, B0−B3 = The levels of the respective Data−Word Inputs

PIN DESCRIPTIONS

INPUTS

A0−A3 (Pins 2, 5, 11, 14)

Nibble A inputs. The data present on these pins is

transferred to the outputs when the Select input is at a low

level and the Output Enable input is at a low level. The data

is presented to the outputs in inverted form for the LCX258.

B0−B3 (Pins 3, 6, 10, 13)

Nibble B inputs. The data present on these pins is

transferred to the outputs when the Select input is at a high

level and the Output Enable input is at a low level. The data

is presented to the outputs in inverted form for the LCX258.

OUTPUTS

Y0−Y3 (Pins 4, 7, 9, 12)

Data outputs. The selected input nibble is presented at

these outputs when the Output Enable input is at a low level.

The data present on these pins is in its inverted form for the

LCX258. For the Output Enable input at a high level, the

outputs are at a high level for the LCX258.

Select (Pin 1)

Nibble select. This input determines the data word to be

transferred to the outputs. A low level on this input selects

the A inputs and a high level selects the B inputs.

CONTROL INPUTS

Output Enable (Pin 15)

Output Enable input. A low level on this input allows the

selected data to be presented at the outputs. A high level on

this input sets all of the outputs to 3−state off.