MC74LCX158
http://onsemi.com
2
Figure 1. Pinout: 16−Lead Plastic Package (Top View)
1516 14 13 12 11 10
21 34567
V
CC
9
8
E
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 1 Data Inputs
E Enable Input
S Select Input
Yn Outputs
TRUTH TABLE
Inputs Outputs
Output
Enable
Select Y0−Y3
H X H
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 LCX158.
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 LCX158.
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
LCX158. For the Output Enable input at a high level, the
outputs are at a high level for the LCX158.
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
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 a high level for the
LCX158.
