Fairchild Semiconductor 74ACT157SJX, 74ACT157SJ, 74ACT157SCX, 74ACT157SC, 74ACT157PC Datasheet

November 1988

Revised November 1999

74AC157 • 74ACT157 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

■ICC and IOZ reduced by 50%

■Outputs source/sink 24 mA

■ACT157 has TTL-compatible inputs

Ordering Code:

Order Number	Package Number	Package Description
74AC157SC	M16A	16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150” Narrow Body
74AC157SJ	M16D	16-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
74AC157MTC	MTC16	16 -Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm Wide
74AC157PC	N16E	16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300” Wide
74ACT157SC	M16A	16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150” Narrow Body
74ACT157SJ	M16D	16-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
74ACT157MTC	MTC16	16 -Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm Wide
74ACT157PC	N16E	16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300” Wide

Device also available in Tape and Reel. Specify by appending suffix letter “X” to the ordering code.

Logic Symbols

Connection Diagram

IEEE/IEC

Pin Descriptions

	Pin Names		Description
	I0a–I0d		Source 0 Data Inputs
	I1a–I1d		Source 1 Data Inputs
	E		Enable Input
	S		Select Input
	Za–Zd		Outputs

FACT is a trademark of Fairchild Semiconductor Corporation.

Multiplexer Input-2 Quad 74ACT157 • 74AC157

© 1999 Fairchild Semiconductor Corporation

DS009929

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74AC157 • 74ACT157

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 activeLOW. 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			Outputs
E			S		I0	I1	Z
H			X		X	X	L
	L		H		X	L	L
	L		H		X	H	H
	L		L		L	X	L
	L		L		H	X	H

H =	HIGH Voltage Level
L =	LOW Voltage Level
X =	Immaterial

Logic Diagram

Please note that this diagram is provided only for the understanding of logic operations and should not be used to estimate propagation delays.

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Absolute Maximum Ratings(Note 1)

Supply Voltage (V )		− 0.5V to + 7.0V
	CC
DC Input Diode Current (IIK)
VI =	− 0.5V	− 20 mA
VI =	VCC + 0.5V	+ 20 mA
DC Input Voltage (VI)		− 0.5V to VCC + 0.5V
DC Output Diode Current (IOK)
VO =	− 0.5V	− 20 mA
VO =	VCC + 0.5V	+ 20 mA
DC Output Voltage (VO)		− 0.5V to VCC + 0.5V
DC Output Source
or Sink Current (IO)		± 50 mA
DC VCC or Ground Current
per Output Pin (ICC or IGND)		± 50 mA
Storage Temperature (TSTG)		− 65° C to + 150° C
Junction Temperature (TJ)
PDIP		140° C

Recommended Operating

Conditions

Supply Voltage (VCC)
AC	2.0V to 6.0V
ACT	4.5V to 5.5V
Input Voltage (VI)	0V to VCC
Output Voltage (VO)	0V to VCC
Operating Temperature (TA)	− 40° C to + 85° C
Minimum Input Edge Rate (∆ V/∆ t)
AC Devices
VIN from 30% to 70% of VCC
VCC @ 3.3V, 4.5V, 5.5V	125 mV/ns
Minimum Input Edge Rate (∆ V/∆ t)
ACT Devices
VIN from 0.8V to 2.0V
VCC @ 4.5V, 5.5V	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. Fairchild does not recommend operation of FACT circuits outside databook specifications.

DC Electrical Characteristics for AC

Symbol	Parameter	VCC	TA = + 25° C			TA = − 40° C to + 85° C	Units		Conditions
		(V)	Typ		Guaranteed Limits
VIH	Minimum HIGH Level	3.0	1.5	2.1		2.1		VOUT =		0.1V
	Input Voltage	4.5	2.25	3.15		3.15	V	or VCC −			0.1V
		5.5	2.75	3.85		3.85
VIL	Maximum LOW Level	3.0	1.5	0.9		0.9		VOUT =		0.1V
	Input Voltage	4.5	2.25	1.35		1.35	V	or VCC −			0.1V
		5.5	2.75	1.65		1.65
VOH	Minimum HIGH Level	3.0	2.99	2.9		2.9
	Output Voltage	4.5	4.49	4.4		4.4	V	IOUT =		−	50 µ A
		5.5	5.49	5.4		5.4
								VIN =	VIL or VIH
		3.0		2.56		2.46		IOH =	−	12 mA
		4.5		3.86		3.76	V	IOH =	−	24 mA
		5.5		4.86		4.76		IOH =	− 24 mA (Note 2)
VOL	Maximum LOW Level	3.0	0.002	0.1		0.1
	Output Voltage	4.5	0.001	0.1		0.1	V	IOUT =		50 µ A
		5.5	0.001	0.1		0.1
								VIN =	VIL or VIH
		3.0		0.36		0.44		IOL =	12 mA
		4.5		0.36		0.44	V	IOL =	24 mA
		5.5		0.36		0.44		IOL =	24 mA (Note 2)
IIN	Maximum Input	5.5		± 0.1		± 1.0	µ A	VI =	VCC, GND
(Note 4)	Leakage Current
IOLD	Minimum Dynamic	5.5				75	mA	VOLD =		1.65V Max
IOHD	Output Current (Note 3)	5.5				− 75	mA	VOHD =			3.85V Min
ICC	Maximum Quiescent	5.5		4.0		40.0	µ A	VIN =	VCC
(Note 4)	Supply Current							or GND

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.

Note 4: IIN and ICC @ 3.0V are guaranteed to be less than or equal to the respective limit @ 5.5V VCC.

74ACT157 • 74AC157

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