SN54LS155 Datasheet, PDF (1/6 Pages) Motorola, Inc – DUAL 1-OF-4 DECODER/ DEMULTIPLEXER

DUAL 1-OF-4 DECODER/
DEMULTIPLEXER
The SN54 / 74LS155 and SN54 / 74LS156 are high speed Dual 1-of-4
Decoder/Demultiplexers. These devices have two decoders with common
2-bit Address inputs and separate gated Enable inputs. Decoder “a” has an
Enable gate with one active HIGH and one active LOW input. Decoder “b” has
two active LOW Enable inputs. If the Enable functions are satisfied, one
output of each decoder will be LOW as selected by the address inputs. The
LS156 has open collector outputs for wired-OR (DOT-AND) decoding and
function generator applications.
The LS155 and LS156 are fabricated with the Schottky barrier diode
process for high speed and are completely compatible with all Motorola TTL
families.
• Schottky Process for High Speed
• Multifunction Capability
• Common Address Inputs
• True or Complement Data Demultiplexing
• Input Clamp Diodes Limit High Speed Termination Effects
• ESD > 3500 Volts
CONNECTION DIAGRAM DIP (TOP VIEW)
VCC Eb Eb A0 O3b O2b O1b O0b
16 15 14 13 12 11 10 9
NOTE:
The Flatpak version
has the same pinouts
(Connection Diagram) as
the Dual In-Line Package.
1
2
3
4
5
6
78
Ea Ea A1 O3a O2a O1a O0a GND
PIN NAMES
LOADING (Note a)
HIGH
LOW
A0, A1
Ea, Eb
Ea
O0 – O3
Address Inputs
Enable (Active LOW) Inputs
Enable (Active HIGH) Input
Active LOW Outputs (Note b)
0.5 U.L.
0.5 U.L.
0.5 U.L.
10 U.L.
0.25 U.L.
0.25 U.L.
0.25 U.L.
5 (2.5) U.L.
NOTES:
a) 1 TTL Unit Load (U.L.) = 40 µA HIGH/1.6 mA LOW.
b) The Output LOW drive factor is 2.5 U.L. for Military (54) and 5 U.L. for Commercial (74)
Temperature Ranges. The HIGH level drive for the LS156 must be established by an external
resistor.
SN54/74LS155
SN54/74LS156
DUAL 1-OF-4 DECODER/
DEMULTIPLEXER
LS156-OPEN-COLLECTOR
LOW POWER SCHOTTKY
16
1
J SUFFIX
CERAMIC
CASE 620-09
16
1
N SUFFIX
PLASTIC
CASE 648-08
16
1
D SUFFIX
SOIC
CASE 751B-03
ORDERING INFORMATION
SN54LSXXXJ Ceramic
SN74LSXXXN Plastic
SN74LSXXXD SOIC
LOGIC SYMBOL
12
13 3
14 15
E
A0
DECODER a _A1
012 3
A0
E
A1 ^{DECODER b}
0 123
765 4
9 10 11 12
VCC = PIN 16
GND = PIN 8
FAST AND LS TTL DATA
5-262