DM74ALS5245WMX - Fairchild Semiconductor

October 1986

Revised February 2000

DM74ALS5245 Octal 3-STATE Transceiver

DM74ALS5245

Octal 3-STATE Transceiver

General Descript ion

This octal bus transceiver is designed for asynchronous

two-way communication between data buses. The inputs

include hysteresis which provides improved noise rejec-

tion. Data is tra nsmitted either fr om the A bus to the B bus

or from the B bu s to the A bus de pen di ng on the logic level

of the dir ection contr ol (DIR) inp ut. The devic e can be dis-

abled via t he ena ble input ( G) which ca uses the output s to

enter the high impedance mode so the buses are effec-

tively isolated.

Features

■Input Hysteresis

■Low output nois e gene rat i on

■High input noise immunity

■Advanced oxide-isolated, ion implanted Schottky TTL

process

■Switching specificat ion guar anteed o ver the fu ll temper-

ature and VCC range

■PNP inputs to reduce input loading

Ordering Code:

Devices also available in Tape and R eel. Spe ci fy by append ing the suffix let t er “X” to the orderin g c ode.

Connection Diagram

Function Table

L = LOW Logic Lev el H = HIGH Logic Level X = Don't Care (Eit her LOW or HIGH Logic Lev el)

Order Number Package Number Package Description

DM74ALS5245WM M20B 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide

DM74ALS5245SJ M20D 20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide

DM74ALS5245N 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 High Impedance

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DM74ALS5245

Absolute Maximum Ratings(No te 1)

Note 1: The “A bsolute Maxim um Ratin gs” are those valu es beyon d 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

Characteristic tables are not guaranteed at the absolute maximum ratings.

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

Note 2: Plastic DIP package.

Note 3: n = number of device outputs; n−1 outputs switching, each d riv en 0V to 3 V one output @ GND.

Note 4: n = number of device outputs; n outputs switching, n−1 inputs switc hing 0V to 3V. Input under tes t switching 3V to t hreshold (VILD); 0V to threshold

(VIHD); f = 1 MHz.

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 R ange −65°C to +150°C

Typical θJA

N Package 56.0°C/W

M Package 74.0°C/W

Symbol Parameter Min Max Units

VCC Supply Voltage 4.5 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 24 mA

TAFree Air Operating Temp erature Range 0 70 °C

Symbol Parameter Test Conditions Min Typ Max Units

VIK Input Clamp Voltage VCC = Min, I I = −18 mA −1.5 V

HYS Hysteresis (VT+ − VT−)V

CC = Min 0.2 0.32 V

VOH HIGH Level VCC = 4.5V to 5.5V IOH = −0.4 mA VCC − 2

Output Voltage VCC = Min IOH = −3 mA 2.4 3.2 V

IOH = Max 2

VOL LOW Level VCC = Min IOL = 12 mA 0.25 0.4 V

Output Voltage IOL = 24 mA 0.35 0.5

IIInput Current at VCC = Max I/O Ports, VI = 5.5V 100 µA

Maximum Input Voltage Control Inputs, VI = 7V 100

IIH HIGH Level Input Curre nt VCC = Max, VI = 2.7V 20 µA

IIL LOW Level Input Current VCC = Max, VI = 0.4V −100 µA

IOOutput Drive Current VCC = Max, VO = 2.25V −30 −112 mA

ICC Supply Current VCC = Max Outputs HIGH 30 45

Outputs LOW 36 55 mA

Outputs Disabled 38 58

VOLP Quiet Output Maximum VCC = 5.0V, TA = 25°C0.5 V

Dynamic VOL (Figures 1, 2 ; (Note 2)(Note 3))

VOLV Quiet Output Minimum VCC = 5.0V, TA = 25°C−0.2 V

Dynamic VOL (Figures 1, 2 ; (Note 2)(Note 3))

VIHD Minimum High Level VCC = 5.0V, TA = 25°C1.6 V

Dynamic Input Voltage (Note 2)(Note 4)

VILD Maximum Low Level VCC = 5.0V, TA = 25°C1.0 V

Dynamic Input Voltage (Note 2)(Note 4)

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DM74ALS5245

Switching Characteristics

over recommended operating free air temperature range

Symbol Parameter Conditions From (Input) Min Max Units

To (Output)

tPLH Propagation Delay Time VCC = 4.5V to 5.5V, A or B to B or A 3 10 ns

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

tPHL Propagation Delay Time CL = 50 pF A or B to B or A 3 10 ns

HIGH-to-LOW Level Output

tPZH Output Enable Time G to A or B 5 20 ns

to HIGH Level Output

tPZL Output Enable Time G to A or B 5 20 ns

to LOW Level Output

tPHZ Output Disable Time G to A or B 2 10 ns

from HIGH Level Output

tPLZ Output Disable Time G to A or B 4 15 ns

from LOW Level Output

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DM74ALS5245

ALS Noise Characteristics

The setup of a noise characteristics measurement is critical

to the accuracy and repeatability of the tests. The following

is a brief description of the setup used to measure the

noise characteristics of ALS.

Equipment:

Word Generator

Printed Circuit Board Test Fixture

Dual Trace Oscilloscope

Procedure:

1. Verify Test Fixture Loading: Standard Load 50 pF,

500Ω.

2. Deskew the word generator so that no two channels

have greater than 150 ps skew between them. This

requires that the oscilloscope be deskewed first. Swap

out the channels that have more than 150 ps of s kew

until all channels being used are within 150 ps. It is

important to deskew the word generator channels

before te sting. This will ensure that the outputs switch

simultaneously.

3. Terminate all inp uts a nd o utp uts to ens ure proper load -

ing of the outputs and that the input levels are at the

correct vol ta ge.

4. Set VCC to 5.0V.

5. Set the word generator to toggle all but one output at a

frequency of 1 MHz. Greater frequencies will increase

DUT heating and affect the results of the measure-

ment.

6. S et the word gene rator inp ut leve ls at 0V LOW an d 3V

HIGH. Verify levels with a digital volt meter.

FIGURE 1. Quiet Output Noise Voltage Waveforms

Note 5: VOHV and VOHP are measured with respect to VOH reference. VOLV

and VOLP are measured with respec t to ground referenc e.

Note 6: Input pulses have the following characteristics: f = 1 MHz, tr = 3ns,

tf = 3 ns, skew < 150 ps.

VOLP/VOLV and VOHP/VOHV:

• Determine the quiet output pin that demonstrates the

greatest noise levels. The worst case pin will usually be

the furthe st fr om the gr ound pin. Monito r the outp ut volt -

ages usin g a 50 Ω coaxial ca ble p lugged into a sta ndard

SMB type connector on the test fixture. Do not use an

active FET probe.

• Measure V OLP and VOLV on the quiet output during the

HL transition. Measure VOHP and VOHV on the quiet out-

put during the LH transition.

• Verify that the GND reference recorded on the oscillo-

scope has not drifted to ensure the accuracy and repeat-

ability of the measurements.

VILD and VIHD:

• Monitor one of the switching outputs using a 50Ω coaxial

cable plugged into a standard SMB type connector on

the test fixture. Do not use an active FET probe.

• First increase the input LOW voltage leve l, VIL, until the

output begins to oscillate. Oscillation is defined as noise

on the output LOW level that exceeds VIL limits, or on

output HIGH levels that exceed VIH limits. The input

LOW voltage level at which oscillation occ urs is defined

as VILD.

• Next decre ase the inpu t HIGH volta ge level on the word

generat or, VIH until the output begins to oscillate. Oscil-

lation is defined as noise on the output LOW level that

exceeds V IL limits, or on output HIGH levels that exceed

VIH limits. The input HI GH v oltage level at which o scilla-

tion occurs is defined as VIHD.

• Verify that the GND reference recorded on the oscillo-

scope has not drifted to ensure the accuracy and repeat-

ability of the measurements.

FIGURE 2. Simultaneous Switching Test Circuit

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DM74ALS5245

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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DM74ALS5245

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

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

Package Number M20D

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DM74ALS5245 Octal 3-STATE Transceiver

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 descr ibed, no circuit patent 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

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to perform when properly used in accordance with

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