DM74AS245SJX - Fairchild Semiconductor

October 1986

Revised February 2000

DM74AS245 Octal Bus Transceiver with 3-STATE Outputs

DM74AS245

Octal Bus Transceiver with 3-STATE Outputs

General Descript ion

This advanced Schottky device contains 8 pairs of

3-STATE logi c elem ents con figure d as octa l bu s transc eiv-

ers. These circ uits ar e design ed for use i n m emory, micr o-

processor syst ems and in asynchro nous bidirectional data

buses. Two way communication between buses is con-

trolled by th e (DIR) inp ut. Data tr ansmits eithe r from the A

bus to the B bus or from the B bus to the A bus. Both t he

driver and receiver outputs can be disabled via the (G)

enable input which causes outputs to enter the high imped-

ance mode so that the buses are effectively isolated.

Features

■Advanced oxide-isolated, ion-implanted Schottky

TTL process

■Non-inverting logic output

■3-STATE outputs independently controlled on

A and B buses

■Low outp ut impedance to drive terminate d transmission

lines to 133Ω

■Switching response specified into 500Ω/50 pF

■Specified to interface with CMOS at VOH = VCC − 2V

■PNP inputs reduce input loading

■Switching specifications guaranteed over full

temperature and VCC range

Ordering Code:

Devices also available in Ta pe and R eel. Speci fy by append ing the suffix let t er “X” to the o rdering c ode.

Connection Diagram Function Table

Order Number Package Number Package Description

DM74AS245WM M20B 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide

DM74AS245SJ M20D 20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide

DM74AS245N N20A 20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide

Control

Inputs Operation

GDIR

L L B Data to A Bus

L H A Data to B Bus

H X Hi-Z

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DM74AS245

Absolute Maximum Ratings(No te 1)

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

the saf ety of the device cannot be guarante ed. The device s hould not be

operated at these limits. The parametric values defined in the Electrical

Characteristics tables are not gua rant eed at the absolute maximum ratin gs.

The “Re comme nded Operat ing Co ndition s” table will define the cond itions

for actu al device operation.

Recommended Operating Conditions

Electrical Characteristics

over recommended operating free air temper ature range

Switching Characteri stics

over recommended operating free air temper ature range

Supply Voltage, VCC 7V

Input Voltage

Control Inputs 7V

I/O Ports 5.5V

Operating Free Air Temperature Range 0°C to 70°C

Storage Temper ature Range −65°C to +150°C

Typical θJA

N Package 51.5°C/W

M Package 76.0°C/W

Symbol Parameter Min Typ 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 −15 mA

IOL LOW Level Output Current 48 mA

TAFree Air Operating Temperature 0 70 °C

Symbol Parameter Conditions Min Typ Max Units

VIK Input Clamp Voltage VCC = 4.5V, IIN = −18 mA −1.2 V

VOH HIGH Level Output VCC = 4.5V, IOH = −3 mA 2.4 3.2

Voltage VCC = 4.5V, IOH = −15 mA 2 2.3 V

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

VOL LOW Level Output Voltage VCC = 4.5V, IOL = Max 0.35 0.55 V

IIInput Current at Max VCC = 5.5V, VIN = 7V, 0.1 mA

Input Voltage (VIN = 5.5V for A or B Ports)

IIH HIGH Level Input Curre nt VCC = 5.5V, Control Inputs 20 µA

VIN = 2.7V A or B Ports 70

IIL LOW Level Input Current VCC = 5.5V, Control Inputs −0.5 mA

VIN = 0.4V A or B Ports −0.75

IOOutput Drive Current VCC = 5.5V, VOUT = 2.25V −50 −150 mA

ICC Supply Current VCC = 5.5V Output HIGH 62 97

Output LOW 95 149 mA

3-STATE 79 123

Symbol Parameter Conditions From To Min Max Units

tPLH Propagati on Delay T i me VCC = 4.5V to 5.5V, A or B B or A 2 7.5 ns

HIGH-to-LOW Level Output R1 = R2 = 500Ω,

tPHL Propagation Del ay T ime CL = 50 pF A or B B or A 2 7 ns

HIGH-to-LOW Level Output

tPZL Output Enable Time to LOW Level G A or B 2 8.5 ns

tPZH Output Enable Time to HIGH Level G A or B 2 9 ns

tPLZ Output Disable Time from LOW Level G A or B 2 9.5 ns

tPHZ Output Disable Time from HIGH Leve l G A or B 2 5.5 ns

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DM74AS245

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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DM74AS245

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

20-Lead Sma ll Outline Pack age (SOP), EIAJ TYPE I I, 5.3mm Wide

Package Number M20D

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DM74AS245 Octal Bus Transceiver with 3-STATE Outputs

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

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

Packag e Num be r N20A

Fairchild does not assume any responsibility for use of any circu itry described , no circuit patent licenses are implied and

Fairchild reserves the right at any time without notice to change said circuitry and specifications.

LIFE SUPPORT POLICY

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 suppor t de vices o r syst ems 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

instruct ions fo r use pr ovi de d in the labe l ing, can be re a-

sonably expected to result in a significant injury to the

user.

2. A criti cal com ponen t in any compo nent o f a l ife supp ort

device or system whose failure to perform can be rea-

sonabl y e xpec ted to c ause th e fa i lure of the li fe s upp or t

device or system, or to affect its safety or effectiveness.