Fairchild Semiconductor DM74LS245WMX, DM74LS245WM, DM74LS245SJX, DM74LS245SJ, DM74LS245N Datasheet

August 1986

Revised March 2000

DM74LS245

3-STATE Octal Bus Transceiver

General Description

These octal bus transceivers are designed for asynchronous two-way communication between data buses. The control function implementation minimizes external timing requirements.

The device allows data transmission from the A Bus to the B Bus or from the B Bus to the A Bus depending upon the logic level at the direction control (DIR) input. The enable input (G) can be used to disable the device so that the buses are effectively isolated.

Features

■Bi-Directional bus transceiver in a high-density 20-pin package

■3-STATE outputs drive bus lines directly

■PNP inputs reduce DC loading on bus lines

■Hysteresis at bus inputs improve noise margins

■Typical propagation delay times, port-to-port 8 ns

■Typical enable/disable times 17 ns

■IOL (sink current)

24mA

■IOH (source current)

−15 mA

Ordering Code:

Order Number	Package Number	Package Description
DM74LS245WM	M20B	20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide
DM74LS245SJ	M20D	20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
DM74LS245N	N20A	20-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
		Enable			Direction	Operation
					Control
			G
					DIR
			L		L	B Data to A Bus
			L		H	A Data to B Bus
			H		X	Isolation
	H
		= HIGH Level
	L = LOW Level
	X = Irrelevant

Transceiver Bus Octal STATE-3 DM74LS245

© 2000 Fairchild Semiconductor Corporation

DS006413

www.fairchildsemi.com

DM74LS245

Absolute Maximum Ratings(Note 1)

Supply Voltage			7V
Input Voltage
			7V
DIR or	G
A or B			5.5V
Operating Free Air Temperature Range			0°C to +70°C
Storage Temperature Range			−65°C to +150°C

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	4.75	5	5.25	V
VIH	HIGH Level Input Voltage	2			V
VIL	LOW Level Input Voltage			0.8	V
IOH	HIGH Level Output Current			−15	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 (unless otherwise noted)

Symbol

Parameter

Conditions

Min

Typ

Max

Units

(Note 2)

VI

Input Clamp Voltage

VCC = Min, II = −18 mA

−1.5

V

HYS

Hysteresis (VT+ − VT−)

VCC = Min

0.2

0.4

V

VOH

HIGH Level

VCC = Min, VIH = Min

2.7

Output Voltage

VIL = Max, IOH = −1 mA

VCC = Min, VIL = Min

2.4

3.4

V

VIL = Max, IOH = −3 mA

VCC = Min, VIH = Min

2

VIL = 0.5V, IOH = Max

VOL

LOW Level

VCC = Min

IOL = 12 mA

0.4

Output Voltage

VIL = Max

IOL = Max

0.5

V

VIH = Min

IOZH

Off-State Output Current,

VCC = Max

VO = 2.7V

20

μA

HIGH Level Voltage Applied

VIL = Max

IOZL

Off-State Output Current,

VIH = Min

VO = 0.4V

−200

μA

LOW Level Voltage Applied

II

Input Current at Maximum

VCC = Max

A or B

VI = 5.5V

0.1

mA

VI = 7V

Input Voltage

DIR or G

0.1

IIH

HIGH Level Input Current

VCC = Max, VI = 2.7V

20

μA

IIL

LOW Level Input Current

VCC = Max, VI = 0.4V

−0.2

mA

IOS

Short Circuit Output Current

VCC = Max (Note 3)

−40

−225

mA

ICC

Supply Current

Outputs HIGH

48

70

Outputs LOW

VCC = Max

62

90

mA

Outputs at Hi-Z

64

95

Note 2: All

typicals are at VCC = 5V, TA = 25°C.

Note 3: Not more than one output should be shorted at a time, not to exceed one second duration

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