Document
www.DataSheet4U.com
54AC157 • 54ACT157 Quad 2-Input Multiplexer
July 1998
54AC157 • 54ACT157 Quad 2-Input Multiplexer
General Description
The ’AC/’ACT157 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 outputs present the selected data in the true (noninverted) form. The ’AC/ ’ACT157 can also be used as a function generator.
Features
n n n n ICC and IOZ reduced by 50% Outputs source/sink 24 mA ’ACT157 has TTL-compatible inputs Standard Microcircuit Drawing (SMD) — ’AC157: 5962-89539 — ’ACT157: 5962-89688
Logic Symbols
IEEE/IEC
DS100272-1
DS100272-2
Pin Names I0a–I0d I1a–I1d E S Za–Zd
Description Source 0 Data Inputs Source 1 Data Inputs Enable Input Select Input Outputs
Connection Diagrams
Pin Assignment for DIP and Flatpak Pin Assignment for LCC
DS100272-3
DS100272-4
FACT™ is a trademark of Fairchild Semiconductor Corporation.
© 1998 National Semiconductor Corporation
DS100272
www.national.com
Functional Description
The ’AC/’ACT157 is a quad 2-input multiplexer. 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 ’AC/’ACT157 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 shown below: Za = E • (I1a • S + I0a • S) Zb = E • (I1b • S + I0b • S) Zc = E • (I1c • S + I0c • S) Zd = E • (I1d • S + I0d • S) A common use of the ’AC/ACT157 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 ’AC/’ACT157 can generate any four of the sixteen different functions of two variables with one variable common. This is useful for implementing gating functions.
Truth Table
Inputs E H L L L L S X H H L L I0 X X X L H I1 X L H X X Outputs Z L L H L H
H = HIGH Voltage Level L = LOW Voltage Level X = Immaterial
Logic Diagram
DS100272-5
Please note that this diagram is provided only for the understanding of logic operations and should not be used to estimate propagation delays.
www.national.com
2
Absolute Maximum Ratings (Note 1)
If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Supply Voltage (VCC) DC Input Diode Current (IIK) VI = −0.5V VI = VCC + 0.5V DC Input Voltage (VI) DC Output Diode Current (IOK) VO = −0.5V VO = VCC + 0.5V DC Output Voltage (VO) DC Output Source or Sink Current (IO) DC VCC or Ground Current per Output Pin (ICC or IGND) Storage Temperature (TSTG) Junction Temperature (TJ) CDIP −0.5V to +7.0V −20 mA +20 mA −0.5V to VCC + 0.5V −20 mA +20 mA −0.5V to VCC + 0.5V
Recommended Operating Conditions
Supply Voltage (VCC) ’AC ’ACT Input Voltage (VI) Output Voltage (VO) Operating Temperature (TA) 54AC/ACT Minimum Input Edge Rate (∆V/∆t) ’AC Devices VIN from 30% to 70% of VCC VCC @ 3.3V, 4.5V, 5.5V Minimum Input Edge Rate (∆V/∆t) ’ACT Devices VIN from 0.8V to 2.0V VCC @ 4.5V, 5.5V 2.0V to 6.0V 4.5V to 5.5V 0V to VCC 0V to VCC −55˚C to +125˚C
125 mV/ns
± 50 mA ± 50 mA −65˚C to +150˚C
175˚C
125 mV/ns
Note 1: Absolute maximum ratings are those values beyond which damage to the device may occur. The databook specifications should be met, without exception, to ensure that the system design is reliable over its power supply, temperature, and output/input loading variables. National does not recommend operation of FACT™ circuits outside databook specifications.
DC Characteristics for ’AC Family Devices
Symbol Parameter VCC (V) VIH Minimum High Level Input Voltage VIL Maximum Low Level Input Voltage VOH Minimum High Level Output Voltage 3.0 4.5 5.5 3.0 4.5 5.5 3.0 4.5 5.5 54AC TA = −55˚C to +125˚C Guaranteed Limits 2.1 3.15 3.85 0.9 1.35 1.65 2.9 4.4 5.4 (Note 2) VIN = VIL or VIH IOH = −12 mA IOH = −24 mA IOH = −24 mA IOUT = 50 µA V (Note 2) VIN = VIL or VIH IOL = 12 mA V µA mA mA IOL = 24 mA IOL = 24 mA VI = VCC, GND VOLD = 1.65V Max VOHD = 3.85V Min V IOUT = −50 µA V VOUT = 0.1V or VCC − 0.1V V VOUT = 0.1V or VCC − 0.1V Units Conditions
3.0 4.5 5.5 VOL Maximum Low Level Output Voltage 3.0 4.5 5.5
2.4 3.7 4.7 0.1 0.1 0.1 V
3.0 4.5 5.5 IIN IOLD IOHD Maximum Input Leakage Current Minimum Dynamic Output Current (Note 3) 5.5 5.5 5.5
0.50 0.50 0.50
± 1.0
50 −50
3
www.national.com
DC Characteristics for ’AC Family Devices
Symbol Parameter VCC (V) ICC Maximum Quiescent Supply Current
Note 2: All outputs loaded; thresholds on input associated with output under test. Note 3: Maximum test duration 2.0 ms, one output loaded at a time.
(Continued)
54AC TA = −55˚C to +125˚C Guaranteed Limits 80.0
Units
Condition.