Datasheet DM74ALS245AWMX, DM74ALS245AWM, DM74ALS245ASJX, DM74ALS245ASJ, DM74ALS245AN Datasheet (Fairchild Semiconductor)

© 2000 Fairchild Semiconductor Corporation DS006213 www.fairchildsemi.com

September 1986
Revised February 2000

DM74ALS245A Octal 3-STATE Bus T ransceiver

DM74ALS245A
Octal 3-STATE Bus Transceiver

General Description

This advanced low power Schot tky dev ice contains 8 pa irs
of 3-STATE logic elements configured as octal bu s trans­ceivers. These circuits are de signed for use in memory,
microprocessor systems an d in asynch ronou s bidir ectional
data buses. Two way communication between buses is
controlled by the (DIR) input. Data transmits either from the
A bus to the B bus or from the B bus to the A bus. Both the
driver and receiver outputs can be disabled via the (G

)
enable input which causes outputs to enter the high imped­ance mode so that the buses are effectively isolated.

Features

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

■ Non-inverting logic output

■ Glitch free bus during power up and down

■ 3-STAT E outputs independently controlled on A and B

buses

■ Low output impedance to drive terminate d transmission
lines to 133Ω

■ Switching response specified into 500Ω/50 pF

■ Specified to interface with CMOS at V

OH

= VCC − 2V

■ PNP inputs to reduce input loading

■ Switching specifications guaranteed over full tempera-

ture and V

CC

range

Ordering Code:

Devices also availab le in Tape and Reel. Specify by appending th e s uffix let t er “X” to the ordering code.

Connection Diagram Function Table

H = HIGH Logic Level
L = LOW Logic Level

X = Either HIGH or LOW Logi c L ev el

Order Number Package Number Package Description

DM74ALS245AWM M20B 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide
DM74ALS245ASJ M20D 20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
DM74ALS245AMSA MSA20 20-Lead Shrink Small Outline Package (SSOP), EIAJ TYPE II, 5.3mm Wide
DM74ALS245AN N20A 20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide

Control

Inputs Operation

G

DIR

L L B Data to A Bus
L H A Data to B Bus

H X Hi-Z

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DM74ALS245A

Absolute Maximum Ratings(Note 1)

Note 1: The “Absolute Maximum Ratings” are those values beyond which

the safety of the dev ice cannot be guaranteed. T he device sh ould not be
operated at these limits. The parametric values defined in the Electrical
Characteristics tables are not guaranteed at the absolute maximum ratings.
The “Recommend ed O peratin g Cond itions” t able w ill defin e the co ndition s
for actual device operation.

Recommended Operating Conditions

Electrical Characteristics

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

Switching Characteristics (Note 2)

over recommended operating free air temperature range

Note 2: Switching c haracteristic conditi ons are VCC = 4.5V to 5.5V, RL = 500Ω, CL = 50 pF.

Supply Voltage 7V
Input Voltage

Control Inputs 7V

I/O Ports 5.5V
Operating Free Air Temperature Range 0°C to +70°C
Storage Temperature Range −65°C to +150°C
Typical θ

JA

N Package 53.0°C/W

M Package 72.0°C/W

Symbol Parameter Min Typ Max Units

V

CC

Supply Voltage 4.5 5 5.5 V

V

IH

HIGH Level Input Voltage 2 V

V

IL

LOW Level Input Voltage 0.8 V

I

OH

HIGH Level Output Current −15 mA

I

OL

LOW Level Output Current 24 mA

T

A

Operating Free Air Temperature 0 70 °C

Symbol Parameter Conditions Min Typ Max Units

V

IK

Input Clamp Voltage VCC = 4.5V, IIN = −18 mA −1.5 V

V

OH

HIGH Level VCC = 4.5V, IOH = −3 mA 2.4 3.2 V
Output Voltage VCC = 4.5V, IOH = Max 2 2.3 V

IOH = −0.4 mA, VCC = 4.5V to 5.5V VCC − 2V

V

OL

LOW Level Output Voltage VCC = 4.5V IOL = 24 mA 0.35 0.5 V

I

I

Input Current at Maximum VCC = 5.5V VIN = 7V Control Inputs 0.1

mA

Input Voltage VIN = 5.5V A or B Ports 0.1

I

IH

HIGH Level Input Current VCC = 5.5V, VIN = 2.7V 20 µA

I

IL

LOW Level Input Current VCC = 5.5V, VIN = 0.4V −0.1 mA

I

O

Output Drive Current VCC = 5.5V, V

OUT

= 2.25V −30 −112 mA

I

CC

Supply Current VCC = 5.5V Outputs HIGH 30 45 mA

Outputs LOW 36 55 mA
3-STATE 38 58 mA

Symbol Parameter Circuit Configuration Min Max Units

t

PLH

Propagation Delay Time

310ns

LOW-to-HIGH Level Output

t

PHL

Propagation Delay Time

310ns

HIGH-to-LOW Level Output

t

PZL

Output Enable Time to LOW Level 5 20 ns

t

PZH

Output Enable Time to HIGH Level 5 20 ns

t

PLZ

Output Disable Time from LOW Level 4 15 ns

t

PHZ

Output Disable Time from HIGH Level 2 10 ns

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DM74ALS245A

Physical Dimensions inches (millimeters) unless otherwise noted

20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide

Package Number M20B

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DM74ALS245A

Physical Dimensions inches (millimeters) unless otherwise noted (Continued)

20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide

Package Number M20D

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DM74ALS245A

Physical Dimensions inches (millimeters) unless otherwise noted (Continued)

20-Lead Shrink Small Outline Package (SSOP), EIAJ TYPE II, 5.3mm Wide

Package Number MSA20

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DM74ALS245A Octal 3-STATE Bus T ranscei ver

Physical Dimensions inches (millimeters) unless otherwise noted (Continued)

20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide

Package Number N20A

Fairchild does not assume any responsibility for use of any circuitry described, no circuit pate nt licenses are implied and
Fairchild reserves the right at any time without notice to change said circuitry and specifications.

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FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT
DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD
SEMICONDUCTOR CORPORATION. As used herein:

1. Life support devices or systems are devices or syste ms

which, (a) are intended for surgical implant into the
body, or (b) support or sustain life, and (c) whose failure
to perform when properly used in accordance with
instructions for use provided in the labeling, can be rea­sonably expected to result in a significant inju ry to the
user.

2. A critical component i n any compon ent of a lif e support
device or system whose failu re to perform can be rea­sonably expected to ca use the fa i lure of the life su pp ort
device or system, or to affect its safety or effectiveness.

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