TYPE SN74LS362 (TIM9904) FOUR-PHASE CLOCK GENERATOR/DRIVER BULLETIN NO. DL-S , OCTOBER 1976-REVISED AUGUST 1977 V CC 2 1 IN OUT TTL TTL VDO

(1)

TTL

MSI

TYPE SN74LS362

(TIM9904)

FOUR-PHASE CLOCK GENERATOR/DRIVER

BULLETIN

NO.DL-S 7712476,

OCTOBER

1976-REVISED

AUGUST

1977

Clock

Generator/Driver

for

The

TMS

9900

or

Other

Microprocessors

High-Level

4-Phase

Outputs

Complementary

TTL

4-Phase

Outputs

Self-Contained

Oscillator

Can

be

Crystal

or Capacitor Controlled

External

Oscillator

Can Be Used

Clocked D-Type

Flip-Flop

With

Schmitt-Trigger Input

For Reset

Signal

Synchronization

description

SN74LS362...J

OR N PACKAGE

(TOP VIEW!

XTAL XTAL OSC OSC $2 *1

VCC 2 1 IN OUT TTL TTL VDO «’1

r

|

r

XTAL XTAL OSC 2 1 IN TANK1 TANK2 FFQ 06C Jj *1 *1 OUT TTL TTL «P2 FFD TTL TTL *3 *4

E

TANK TANKGND FFQ FFD «A *3 <M OND

1 2 1 TTL TTL 2

The

'LS362consistsofanoscillator,divide-by-fourcounter,aseconddivide-by-fourcounterwithgatingtogenerate four clock phases,high-level(12-volt) outputdrivers,low-level(5-volt) complementary outputdrivers,andaD-type flip-flopcontrolledby anexternalsignaland the

#3

clock.

The

fourhigh-levelclock phases provide clock inputs to a

TMS

9900

microprocessor.

The

fourcomplementary TTL-level clocks can be used totime

memory

or other logic

functionsina

TMS

9900

computer system.

The

D-typeflip-flopcanbe usedto provide(forexample)areset signaltoa

TMS

9900, timedby$3,onreoeiptof aninput tothe

FFD

inputfrom

power

turn-on oramanualswitch closure.Other

applicationsarepossible.

A

safety featurehasbeenincorporatedinthe<t>outputs suchthatifanopenoccursinthe

Vcc

supply

common

to'LS362 and

TMS

9900,the<t>outputswillgo lowthus protecting the

TMS

9900.

The

frequencyofthe internal oscillatorcan beestablished

by

a quartz crystal orcapacitorand

LC

circuit.Eithera fundamental or overtonecrystal

may

beused.

The

LC

circuitconnected to thetankinputsselectsthe desiredcrystal overtone orestablishesthe internal oscillatorfrequency

when

acapacitorisused instead of acrystal.

An LC

circuit must always be usedatthetankinputs

when

using theinternal oscillator.

An

externaloscillatorcanbeused,ifdesired, see"ApplicationsInformation"fordetails.

typical

phase

relationships

of

inputs

and

outputs

(OSC

isinternal)

OSC1N

_|

I

oscTJTJTJTJTJTJXnJTJTJTJTJTJTJT^

oscout | | | | | 1 | | | 1 | 1 | | T1 *i

2_

*3

_{_}

**_

31

_{_}

?3~

?4~

FFD

-FF0

-1.

_r

“L

Texas

Instruments

INCORPORATED

POSTOFFICEBOXH12•DALLAS.TEXAS75222

877

7480

(2)

(3)

TYPE SN74LS362

(TIM9904)

FOUR-PHASE CLOCK GENERATOR/DRIVER

schematics of

inputs

and

outputs

absolute

maximum

ratings

over operating

free-air

temperature range

(unless

otherwise

noted)

Supplyvoltage:

Vpc

(seeNote1) 7

V

VqD

(seeNote1) 13

V

Input voltage:

OSCIN

5.5

V

FFD

-0.5

V

to 7

V

Operatingfree-airtemperaturerange

0°C

to

70°C

Storagetemperaturerange

—

65°Cto150°C

NOTE

1: Voltaga value* arewithreapect to th#network groundterminal!connectedtogether.

operating

conditions

MIN

NOM

MAX

UNIT

Supplyvoltages

Vcc

4,76 5

6.26

V

D

11.4 12 12.6

V

High-leveloutputcurrent,Iqh

0t,02,03,04 -100

mA

Ailothers

-400

HA Low-leveloutputcurrent,Iql 01,02,03,04

4

mA

Allothers 8

mA

Internaloscillatorfrequency,f0jc 48 54

MHz

External oscillator pulsewidth, ty^ox;) 25 ns

Setuptime,

FFD

input (with respect tofallingedgeof 03), t^j 50 ns

Holdtime,

FFD

input (with respecttofellingedgeof 03),tfo

-30

n#

Operatingfree-airtemperature, 0 70 L'c

7-462

877

Texas

Instruments

INCORPORATED

(4)

TYPE SN74LS382

(TIM99B4)

FOUR-PHASE CLOCK 6EHERAT0R/DRIVER

REVISED

AUGUST

1977

etoctrtcalcharacteristics

war

racom

mended

operating

freo*air

temperature range

(unless

otherwise

noted)

PARAMETER

TEST CONDITIONS

MIN

TYPt

MAX

UNIT

V|h High-level input voltage

2 V

Low-level

Vm

input voltage

PFD

0.5

V

OSCIN 0.8

Vt>-V

T

_

Hysteresis

FFD

d

0 V

V|k Inputclampvoltage

Vcc"-6V.

V0

D“

11.4V,l|

-—18mA

-1.5

V

High-level

v

OH

outputvoltage 01,02, 03,04

Vcc

“ 4-76 V,

V

_D

_o-

11.4

V

to12.6

V

lOH-

-100

J|A

Vqq-2 Vqq—

1.5

Vqq

V

Other outputs _'OH"

—

A00,|A 2.7 3.4 Low-level

VOL

outputvoltage 01,02,03,04

Vcc-

4.7SV,

Vqq

-11.4

V

|QL

“4

mA

0.25 0.4

mA

Other outputs lOL

*4

mA

0.25 0.4 'OL

"8

mA

0.35 0.5 Input current at

li

maximum

input voltage

FFD

V

CC -6.25V,

_VDD

-12.6

V

V|

-7 V

0.1

mA

OSCIN

V|- 5.5

V

0.3 High-level l|H inputcurrent

FFD

Vcc

-5.25V,

VDD

- 12.6 V, V|-2.7

V

20

pA

OSCIN 60 Low-level *,L input current

FFD

Vcc

-6.26V,

Vqq

- 12.6 V,

V|-

0.4

V

-0.4

mA

OSCIN -3.2 Short-cirouit outputcurrentt Allexcept 01,02, 03,04

Vcc

- 5.25

V

-20 -100

mA

ICC Supplycurrentfrom

VqC

Vcc

* 5.25 V,

FFD

andOSCINat

GND,

Outputsopen 106

175

mA

IDD Supplycurrentfrom

Vqd

Vcc

-5.25V,

VDD

- 12.6 V,

FFD

and

OSCIN

at

GNO,

Outputsopen

12 20

mA

t AIItypical valua* araatV

_cc

- 5V,

Vqq

-12V,T

_A

- 25°C.

tNotmorathanona output shouldbe shorted at a time,andduration oftha short-circuitshouldnotexceed onesecond.Outputs01, 02, 03,

and04do not haveshort-circuitprotection.

switching

characteristics,

Ta

-

26°

C

r

Vcc

“ 6

v

*

V

DD

»

12 V,

-

48 MHz,

see figure1

PARAMETER

*out Output frequency, any0or0

TTL

*out Output fraquancy,

OSCOUT

*c<0) Cycletime,eny0output

V(0| Rise time,any0output l_f(0l Isailtime,any0output

V<0) Pultt width,eny0outputhigh

<«1L,*2H Delaytime,01 lowto02high

*42L,4>3H Delaytime,02lowto03high **3L.04H Delaytime,03lowto04high «*4L.«1H Delaytime,04lowto01high

Delaytime,01highto02high «*2H.*3H Delaytime,02high to

03

high

Delaytime,03highto04high «*4H.*1H Delaytime,04high to01high

•4H.0TL

Delaytime,0nhighto0n

TTL

tow Delaytime,0n lowto0n

TTL

high V3L,

QH

Delaytima,03lowto

FFQ

outputhigh V3L.

QL

Delaytime,03towto

FFQ

output low

>*L.

OSOH

Delaytima,0lowto

OSCOUT

high

OSOL

Delaytime,

FFQ

high to

OSCOUT

low

MIN

TYP

MAX

UNIT

3

MHz

12

MHz

333 ns 5 20 ns 5 20 ns 40 ns 0 6 IS ns 0 5 15 ns 0 5 IS ns 0 5 IS ns 70 83 ns 70 83 ns 70 83 ns 70 83 ns

-8

ns -19 ns -7 n* -12 ns -5 ns -13 ns

TEST

CONDITIONS

Outputloads: 01,03,04: 100 pF

toGND

02:200 pF

toGND

Others:

_Rl

“ 2k«,

C

L«15 pF SeeNote 2

NOTE

2: Useloadcircuitforbi-statetotem-poleoutputs,p

877

Texas

Instruments

INCORPORATED

postoPFiceeoxsoi 2. Dallas,tkxas7»aat

(5)

(6)

TYPE SN74LS392

(TIM9904)

FOUR-PHASE CLOCK 6ENERAT0R/DRIVER

APPLICATION

INFORMATION

Figure2 showsthe'LS362 connectedto e

TMS9900. The

oscillatoris

shown

operatingwitha quartzcrystaland an

LC

circuitconnectedto thetankterminals.

Foroperation of the

TMS

9900

microprocessorat3

MHz,

thefrequency referencewillneedaresonantfrequencyof

48

MHz

(16x 3

MHz).

A

quartzcrystalusedasafrequencyreferenceshouldbe

made

forseries-modeoperationwitha resistancein the20-to

75-ohm

range and becapable of a

minimum

of2

mW

powerdissipation.Typicalfrequency

toleranceis±0.005%. For

48-MHz

operationathird-overtonecrystalisused.

The

inductanceL connectedacrossthe

tankterminalsshouldbe 0.47

pH

± 10%, andthe capacitance

C

(includingboardcapacity)should be 22 pF ± 5%.

The

LC

circuitshouldbe tunedto the third-overtonecrystalfrequencyfor bestresults.

A

0.1-pF capacitorcanbe

substi-tuted for the quartzcrystal. Witha capacitor ratherthana crystal, the

LC

tuned circuit establishestheoperating frequencies.

LC

component

valuesforoperation atany frequency can be

computed

fromf_osc= 1/(2n\/LC) where

foscistheoscillatorfrequency,Listheinductancevalueinhenries,and

C

isthe capacitance valueinfarads.

When

the internaloscillatorisbeing used,

OSCIN

shouldbe connected to

Vcc

througharesistor(1

kH

nominal)and an

LC

tankcircuitmust be connectedto thetank inputs.

An

externaloscillatorcanbeusedby connectingitto

OSCIN

anddisablingtheinternal oscillator

by

connectingthecrystalterminals to

Vcc

and leavingthe tank inputsopen.

An

externaloscillator

must

havea frequency four times the desiredoutputclock frequencyanda

25%

dutycycle.See

Figure3.

The

firstlow-level externalclock pulsewillpreset the divide-by-four counter, allowing the externaloscillator signalto directlydrivethephasegenerator.Figure3isa timingdiagramillustratingoperationwith anexternaloscillator.

Resistorsbetween 01,02, 03. and

04

outputsofthe'LS362 andthecorrespondingclock input terminals of the

TMS

9900

should beinthe 10- to

20-ohm

range (SeeFigure2).Their purposeistominimize overshootand undershoot.

The

required resistancevalueisdependent

on

circuitlayout.Clocksignal interconnectionsshouldbeasshortaspossible.

The

D-typeflip-flopassociatedwithpins

FFD

and

FFQ

can be usedto provide apower-onresetandamanualresetto the

TMS

9900

as

shown

inFigure 4.

A

Schmitt-triggercircuitdriving the

D

input generates afast-rising

waveform

when

the input voltagerisestoaspecificvalue.

At power

tum-on,voltage acrossthe 0.1

pF

capacitorin Figure4will rise towards

Vcc-

This circuitprovides a delay thatresetsthe

TMS

9900

after

Vcc

hasstabilized.

An

optionalmanual resetswitch can be connected to thedelay circuit for resettingthe