SN54/74LS157
QUAD 2-INPUT MULTIPLEXER The LSTTL / MSI SN54 / 74LS157 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 buffered outputs present the selected data in the true (non-inverted) form. The LS157 can also be used to generate any four of the 16 different functions of two variables. The LS157 is fabricated with the Schottky barrier diode process for high speed and is completely compatible with all Motorola TTL families.
• • • • • •
QUAD 2-INPUT MULTIPLEXER
Schottky Process for High Speed Multifunction Capability Non-Inverting Outputs Input Clamp Diodes Limit High Speed Termination Effects Special Circuitry Ensures Glitch Free Multiplexing ESD > 3500 Volts
LOW POWER SCHOTTKY
J SUFFIX CERAMIC CASE 620-09
CONNECTION DIAGRAM DIP (TOP VIEW) VCC 16
E 15
I0c 14
I1c 13
Zc
I0d 11
12
I1d 10
Zd 9
16 1
NOTE: The Flatpak version has the same pinouts (Connection Diagram) as the Dual In-Line Package.
1 S
2 I0a
3 I1d
4 Za
5 I0b
6 I1b
7 Zb
N SUFFIX PLASTIC CASE 648-08
16
8 GND
1
PIN NAMES
LOADING (Note a) LOW
HIGH S E I0a – I0d I1a – I1d Za – Zd
Common Select Input Enable (Active LOW) Input Data Inputs from Source 0 Data Inputs from Source 1 Multiplexer Outputs (Note b)
0.5 U.L. 0.5 U.L. 0.25 U.L. 0.25 U.L. 5 (2.5) U.L.
1.0 U.L. 1.0 U.L. 0.5 U.L. 0.5 U.L. 10 U.L.
D SUFFIX SOIC CASE 751B-03
16 1
ORDERING INFORMATION
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.
SN54LSXXXJ SN74LSXXXN SN74LSXXXD
Ceramic Plastic SOIC
LOGIC DIAGRAM I0a
I1a
2
3
I0b
I1b
5
6
I0c
I1c
14
13
I0d
I1d E S
11
10
15
LOGIC SYMBOL 1
15 2 3 5 6 14 13 11 10
E I0a I1a I0b I1b I0c I1c I0d I1d 1
4
7
Za
9
12
Zb
VCC = PIN 16 GND = PIN 8 = PIN NUMBERS
Zc
Zd
FAST AND LS TTL DATA 5-1
S Za
Zb
Zc
Zd
4
7
12
9
VCC = PIN 16 GND = PIN 8
SN54/74LS157 FUNCTIONAL DESCRIPTION The LS157 is a Quad 2-Input Multiplexer fabricated with the Schottky barrier diode process for high speed. It selects four bits of data from two sources under the control of a common Select Input (S). The Enable Input (E) is active LOW. When E is HIGH, all of the outputs (Z) are forced LOW regardless of all other inputs. The LS157 is the logic implementation of a 4-pole, 2-position switch where the position of the switch is determined by the logic levels supplied to the Select Input. The logic equations for the outputs are:
Za = E ⋅ (I1a ⋅ S + I0a ⋅ S) Zc = E ⋅ (I1c ⋅ S + I0c ⋅ S)
Zb = E ⋅ (I1b ⋅ S + I0b ⋅ S) Zd = E ⋅ (I1d ⋅ S + I0d ⋅ S)
A common use of the LS157 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 LS157 can generate any four of the 16 different functions of two variables with one variable common. This is useful for implementing highly irregular logic.
TRUTH TABLE ENABLE
SELECT INPUT
E
S
I0
I1
Z
H L L L L
X H H L L
X X X L H
X L H X X
L L H L H
INPUTS
OUTPUT
H = HIGH Voltage Level L = LOW Voltage Level X = Don’t Care
GUARANTEED OPERATING RANGES Symbol
Parameter
Min
Typ
Max
Unit
VCC
Supply Voltage
54 74
4.5 4.75
5.0 5.0
5.5 5.25
V
TA
Operating Ambient Temperature Range
54 74
– 55 0
25 25
125 70
°C
IOH
Output Current — High
54, 74
– 0.4
mA
IOL
Output Current — Low
54 74
4.0 8.0
mA
FAST AND LS TTL DATA 5-2
SN54/74LS157 DC CHARACTERISTICS OVER OPERATING TEMPERATURE RANGE (unless otherwise specified) Limits S b l Symbol
P Parameter
VIH
Input HIGH Voltage
VIL
Input LOW Voltage
VIK
Input Clamp Diode Voltage
VOH
Output HIGH Voltage
VOL
Output LOW Voltage
IIH
Min
Typ
Max
U i Unit
2.0 54
0.7
74
0.8 – 0.65
– 1.5
Short Circuit Current (Note 1)
ICC
Power Supply Current
Guaranteed Input p LOW Voltage g for All Inputs
V
VCC = MIN, IIN = – 18 mA
2.5
3.5
V
2.7
3.5
V
VCC = MIN,, IOH = MAX,, VIN = VIH or VIL per Truth Table VCC = VCC MIN, VIN = VIL or VIH per Truth Table
54, 74
0.25
0.4
V
IOL = 4.0 mA
74
0.35
0.5
V
IOL = 8.0 mA
20 40
µA
VCC = MAX, VIN = 2.7 V
mA
VCC = MAX, VIN = 7.0 V
– 0.4 – 0.8
mA
VCC = MAX, VIN = 0.4 V
– 100
mA
VCC = MAX
16
mA
VCC = MAX
0.1 0.2
IOS
V
74
I0, I1 E, S Input LOW Current I0, I1 E, S
V
54
Input HIGH Current I0, I1 E, S
IIL
T Test C Conditions di i Guaranteed Input HIGH Voltage for All Inputs
– 20
Note 1: Not more than one output should be shorted at a time, nor for more than 1 second.
AC CHARACTERISTICS (TA = 25°C) Limits S b l Symbol
P Parameter
Min
Typ
Max
U i Unit
T Test C Conditions di i
tPLH tPHL
Propagation Delay Data to Output
9.0 9.0
14 14
ns
Figure 2
tPLH tPHL
Propagation Delay Enable to Output
13 14
20 21
ns
Figure 1
tPLH tPHL
Propagation Delay Select to Output
15 18
23 27
ns
Figure 2
VCC = 5.0 50V CL = 15 pF
AC WAVEFORMS VIN
VOUT
1.3 V
1.3 V
VIN
tPHL
tPLH
1.3 V
1.3 V
VOUT
Figure 1
1.3 V
1.3 V
tPHL
tPLH
1.3 V
1.3 V
Figure 2
FAST AND LS TTL DATA 5-3