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

© 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