Fairchild Semiconductor DM74ALS244AWMX, DM74ALS244AWM, DM74ALS244ASJX, DM74ALS244ASJ, DM74ALS244AN Datasheet

© 2000 Fairchild Semiconductor Corporation DS006212 www.fairchildsemi.com

September 1986
Revised February 2000

DM74ALS244A Octal 3-STATE Bus Driver

DM74ALS244A
Octal 3-STATE Bus Driver

General Description

This octal 3-STATE bus driver is designed to provide the
designer with flexibility in implementing a bus interface with
memory, microprocessor, or communication systems. This
device offers 64-extended temperature Grade product
guaranteeing perfo rmance from −40°C to +85°C. T he out­put 3-STATE gating control i s organized into two sep arate
groups of four buffers, and both control inpu ts enable the
respective outputs when s et logic LOW. The 3-STATE cir­cuitry contains a feature that maintains the buffer outputs in
3-STATE (high impedance state) during power supply
ramp-up or ramp-down. This eliminates bus glitching prob­lems that arise during power-up and power-down.

Features

■ Advanced low power oxide-isolated ion-implanted
Schottky TTL process

■ Functional and pin compatible with the 74LS counterpart

■ Improved switching per formance with less power dissi-

pation compared with the 74LS counte rpa rt

■ Switching response specified into 500Ω and 50 pF load

■ Switching response specific ations guaranteed over full

temperat ure and V

CC

supply range

■ PNP input design reduces input loading

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 Level Logic State
L = LOW Level Logic State
X = Don't Care (Either LOW or HIGH Level Logic State)
Z = High Impedance (OFF) State

Logic Diagram

Order Number Package Number Package Description

DM74ALS244AWM M20B 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide
DM74ALS244ASJ M20D 20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
DM74ALS244AMSA MSA20 20-Lead Shrink Small Outline Package (SSOP), EIAJ TYPE II, 5.3mm Wide
DM74ALS244AN N20A 20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide

Input Output

G

AY

LL L
LH H

HX Z

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DM74ALS244A

Absolute Maximum Ratings(Note 1)

Note 1: The “Absolute Maximum Ratin gs” are those v alues beyon d 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 (unless otherwise specified)

Switching Characteristics

over recommended operating free-air temperature range

Supply Voltage, V

CC

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 θ

JA

N Package 60.5°C/W
M Package 79.8°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, II = −18 mA −1.5 V

V

OH

HIGH Level VCC = 4.5V to 5.5V IOH = −0.4 mA VCC−2V
Output Voltage VCC = 4.5V IOH = −3 mA 2.4 V

IOH = Max 2 V

V

OL

LOW Level VCC = 4.5V

0.35 0.5 V

Output Voltage IOL = 24 mA

I

I

Input Current at Maximum Input Voltage VCC = 5.5V, VI = 7V 0.1 mA

I

IH

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

I

IL

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

I

O

Output Drive Current VCC = 5.5V, VO = 2.25V −30 −112 mA

I

OZH

HIGH Level 3-STATE Output Current VCC = 5.5V, VO = 2.7V 20 µA

I

OZL

LOW Level 3-STATE Output Current VCC = 5.5V, VO = 0.4V −20 µA

I

CC

Supply Current VCC = 5.5V

915mA

Outputs HIGH
Outputs LOW 15 24 mA
Outputs 3-STATE 17 27 mA

Symbol Parameter Conditions

From

(Input)To(Output)

Min Max Units

t

PLH

Propagation Delay Time VCC = 4.5V to 5.5V,

A Y 3 10 ns

LOW-to-HIGH Level Output CL = 50 pF,

t

PHL

Propagation Delay Time R1 = 500Ω,

A Y 3 10 ns

HIGH-to-LOW Level Output R2 = 500Ω,

t

PZH

Output Enable Time to HIGH Level Output TA = Min to Max G Y 3 20 ns

t

PZL

Output Enable Time to LOW Level Output G Y 3 20 ns

t

PHZ

Output Disable Time from HIGH Level Output G Y 2 10 ns

t

PLZ

Output Disable Time from LOW Level Output G Y 1 13 ns