Document
DM54155 DM74155 Dual 2-Line to 4-Line Decoders Demultiplexers
February 1993
DM54155 DM74155 Dual 2-Line to 4-Line Decoders Demultiplexers
General Description
These TTL circuits feature dual 1-line-to-4-line demultiplexers with individual strobes and common binary-address inputs in a single 16-pin package When both sections are enabled by the strobes the common address inputs sequentially select and route associated input data to the appropriate output of each section The individual strobes permit activating or inhibiting each of the 4-bit sections as desired Data applied to input C1 is inverted at its outputs and data applied at C2 is true through its outputs The inverter following the C1 data input permits use as a 3-to-8-line decoder or 1-to-8-line demultiplexer without external gating
Input clamping diodes are provided on these circuits to minimize transmission-line effects and simplify system design
Features
Y Applications Dual 2-to-4-line decoder Dual 1-to-4-line demultiplexer 3-to-8-line decoder 1-to-8-line demultiplexer
Y Individual strobes simplify cascading for decoding or demultiplexing larger words
Y Input clamping diodes simplify system design
Connection Diagram and Function Tables
Dual-In-Line Package
Select
BA
XX LL LH HL HH XX
2-Line-to-4-Line Decoder or 1-Line-to-4-Line Demultiplexer
Inputs
Outputs
Strobe Data
G1 C1 1Y0 1Y1 1Y2
H X HHH L H LHH L H HLH L H HHL L H HHH X L HHH
1Y3
H H H H L H
TL F 6549 – 1
Order Number DM54155J DM54155W or DM74155N See NS Package Number J16A N16A or W16A
Inputs
Outputs
Select Strobe Data
B A G2
C2 2Y0 2Y1 2Y2 2Y3
XX LL LH HL HH XX
H L L L L X
X HHHH L LHHH L HLHH L HHLH L HHHL H HHHH
C e inputs C1 and C2 connected together G e inputs G1 and G2 connected together H e high level L e low level X e don’t care
3-Line-to-8-Line Decoder or 1-Line-to-8-Line Demultiplexer
Inputs
Outputs
Select
Strobe Or Data
(0)
(1)
(2)
(3)
(4)
(5)
(6)
(7)
C B A G 2Y0 2Y1 2Y2 2Y3 1Y0 1Y1 1Y2 1Y3
X XX L LL L LH L HL L HH H LL H LH H HL H HH
H L L L L L L L L
HHHHHHHH L HHHHHHH H L HHHHHH HH L HHHHH HHH L HHHH HHHH L HHH HHHHH L HH HHHHHH L H HHHHHHH L
C1995 National Semiconductor Corporation TL F 6549
RRD-B30M105 Printed in U S A
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
DM54
b55 C to a125 C
DM74
0 C to a70 C
Storage Temperature Range
b65 C to a150 C
Note The ‘‘Absolute Maximum Ratings’’ are those values 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
Recommended Operating Conditions
Symbol
VCC VIH VIL IOH IOL TA
Parameter
Supply Voltage High Level Input Voltage Low Level Input Voltage High Level Output Current Low Level Output Current Free Air Operating Temperature
Min 45 2
b55
DM54155 Nom 5
Max 55
08 b0 8
16 125
Min 4 75
2
0
DM74155 Nom 5
Max 5 25
08 b0 8
16 70
Units
V V V mA mA C
Electrical Characteristics over recommended operating free air temperature range (unless otherwise noted)
Symbol
Parameter
Conditions
Typ Min
(Note 1)
VI VOH
VOL
II
Input Clamp Voltage
High Level Output Voltage
Low Level Output Voltage
Input Current Max Input Voltage
VCCeMin IIe b12 mA
VCC e Min IOH e Max VIL e Max VIH e Min
VCC e Min IOL e Max VIH e Min VIL e Max
VCC e Max VIe 5 5V
24
IIH
High Level Input Current
VCC e Max VI e 2 4V
IIL
Low Level Input Current
VCC e Max VI e 0 4V
IOS Short Circuit Output Current
VCC e Max (Note 2)
DM54 DM74
b20 b18
ICC Supply Current
VCC e Max (Note 3)
DM54 DM74
Note 1 All typicals are at VCC e 5V TA e 25 C Note 2 Not more than one output should be shorted at a time Note 3 ICC is measured with the outputs open A B and C1 inputs at 4 5V and C2 G1 and G2 inputs grounded
25 25
Max b1 5
04
1 40 b1 6 b55 b55 35 40
Units V V
V
mA mA mA mA
mA
2
Switching Characteristics at VCC e 5V and TA e 25 C (See Section 1 for Test Waveforms and Output Load)
Symbol
Parameter
From (Input) To (Output)
RL e 400X CL e 15 pF Min Max
Units
tPLH
Propagation Delay Time Low to High Level Output
A B C2 G1 or G2 to Y
20 ns
tPHL
Propagation Delay Time High to Low Level Output
A B C2 G1 or G2 to Y
27 ns
tPLH
Propagation Delay Time Low to High Level Output
A or B to Y
32 ns
tPHL
Propagation Delay Time High to Low Level Output
A or B to Y
32 ns
tPLH
Propagation Delay Time Low to High Level Output
C1 to Y
24 ns
tPHL
Propagation Delay Time High to Low Level Output
C1 to Y
27 ns
Logic Diagram
TL F 6549 – 2
3
4
Physical Dimensions inches (millimeters)
16-Lead Ceramic Dual-In-Line Packa.