Fairchild Semiconductor DM74ALS257SJX, DM74ALS257SJ, DM74ALS257N, DM74ALS257MX, DM74ALS257M Datasheet

April 1984

Revised February 2000

DM74ALS257 • DM74ALS258

3-STATE Quad 1-of-2-Line Data Selector/Multiplexer

General Description

These data selectors/multiplexers contain inverters and drivers to supply full on-chip data selection to the four 3- STATE outputs that can interface directly with data lines of bus-organized systems. A 4-bit word selected from one of two sources is routed to the four outputs. The DM74ALS257 presents true data whereas the DM74ALS258 presents inverted data to minimize propagation delay time.

This 3-STATE output feature means that n-bit (paralleled) data selectors with up to 258 sources can be implemented for data buses. It also permits the use of standard TTL registers for data retention throughout the system.

Features

■Switching specifications at 50 pF

■Switching specifications guaranteed over full temperature and VCC range

■Advanced oxide-isolated, ion-implanted Schottky TTL process

■Functionally and pin for pin compatible with Schottky and low power Schottky TTL counterpart

■Improved AC performance over Schottky and low power Schottky counterparts

■3-STATE buffer-type outputs drive bus lines directly

■Expand any data input point

■Multiplex dual data buses

■General four functions of two variables (one variable is common)

■Source programmable counters

Ordering Code:

Order Number	Package Number	Package Description
DM74ALS257M	M16A	16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150 Narrow
DM74ALS257SJ	M16D	16-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
DM74ALS257N	N16E	16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
DM74ALS258M	M16A	16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150 Narrow
DM74ALS258N	N16E	16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide

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

Connection Diagram	Function Table
		Inputs				Output Y
	Output	Select		A	B	DM74ALS257	DM74ALS258
	Control
	H	X		X	X	Z	Z
	L	L		L	X	L	H
	L	L		H	X	H	L
	L	H		X	L	L	H
	L	H		X	H	H	L
	H = HIGH	Level
	L = LOW Level
	X = Don't Care
	Z = High Impedance (OFF)

Selector/Multiplexer Data Line-2-of-1 Quad STATE-3 DM74ALS258 • DM74ALS257

© 2000 Fairchild Semiconductor Corporation

DS006227

www.fairchildsemi.com

DM74ALS257 • DM74ALS258

Logic Diagrams

DM74ALS257

DM74ALS258

www.fairchildsemi.com

2

Absolute Maximum Ratings(Note 1)

Supply Voltage	7V
Input Voltage	7V
Voltage Applied to Disabled Output	5.5V
Operating Free Air Temperature Range	0°C to +70°C
Storage Temperature Range	−65°C to +150°C
Typical θJA
N Package	73.0°C/W
M Package	102.0°C/W

Note 1: 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 tables 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	Parameter	Min	Nom	Max	Units
VCC	Supply Voltage	4.5	5	5.5	V
VIH	HIGH Level Input Voltage	2			V
VIL	LOW Level Input Voltage			0.8	V
IOH	HIGH Level Output Current			−2.6	mA
IOL	LOW Level Output Current			24	mA
TA	Free Air Operating Temperature	0		70	°C

Electrical Characteristics

over recommended operating free air temperature range. All typical values are measured at VCC = 5V, TA = 25°C.

Symbol	Parameter			Conditions		Min	Typ	Max	Units
VIK	Input Clamp Voltage			VCC = 4.5V, II = −18 mA				−1.5	V
VOH	HIGH Level			VCC = 4.5V	IOH = −2.6 mA	2.4	3.3		V
	Output Voltage			IOH = −0.4 mA		VCC − 2			V
VOL	LOW Level			VCC = 4.5V	IOL = 12 mA		0.25	0.4	V
	Output Voltage				IOL = 24 mA		0.35	0.5	V
II	Input Current at Maximum			VCC = 5.5V, VIH = 7V				0.1	mA
	Input Voltage
IIH	HIGH Level Input Current			VCC = 5.5V, VIH = 2.7V				20	μA
IIL	LOW Level Input Current			VCC = 5.5V, VIL = 0.4V				−0.1	mA
IO	Output Drive Current			VCC = 5.5V, VO = 2.25V		−30		−112	mA
IOZH	OFF-State Output Current			VCC = 5.5V,				20	μA
	HIGH Level Voltage Applied			VO = 2.7V
IOZL	OFF-State Output Current,			VCC = 5.5V,				−20	μA
	LOW Level Voltage Applied			VO = 0.4V
ICCH	Supply		DM74ALS257	VCC = 5.5V	Outputs HIGH		3	6	mA
	Current		DM74ALS258	Outputs OPEN			2.5	4	mA
ICCL	Supply		DM74ALS257		Outputs LOW		8	12	mA
	Current		DM74ALS258				7	11	mA
ICCZ	Supply		DM74ALS257		Outputs Disabled		9	14	mA
	Current		DM74ALS258				8	13	mA

DM74ALS258 • DM74ALS257

3	www.fairchildsemi.com