SGS Thomson Microelectronics L6506D, L6506 Datasheet

CURRENTCONTROLLERFOR STEPPING MOTORS

DESCRI P TI ON

The L6506/Dis a linearintegratedcircuit designed
to senseand controlthecurrentinsteppingmotors
and similardevices.Whenusedin conjunctionwith
the L293, L298, L7150,L6114/L6115,the chip set
formsa constantcurrentdrive foran inductiveload
andperformsalltheinterfacefunctionfromthe con­trol logic thruthe powerstage.

Two or more devices may be synchronized using
thesyncpin.In thismodeof operationtheoscillator
in themasterchipsetstheoperatingfrequencyinall
chips.

BLOCK DIAGRAM (pin’s number referred to DIP-18)

L6506

L6506D

DIP18 SO20

ORDERING NUMBERS:

L6506 L6506D

June 1997

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L6506 -L6506D

PI N CONNE CTI ONS (top view)

DIP18 SO20

ABSOLUTEMAXIMUM RATINGS

Symbol Parameter Val u e Uni t

V

V

P

T

T

Supply Voltage 10 V

CC

Input Signals 7 V

i

Total Power Dissipation(T

tot

=70°C) for DIP18

amb

Total Power Dissipation(Tamb =70ÉC) for SO20

JunctionTemperature 150

j

Storage Temperature -40 to 150

stg

1

0.8

THERMAL DATA

Symb o l Parameter DIP 18 SO 20 Uni t

R

thj-amb

ELECTRICAL CHARACTERESTICS (VCC= 5.0V,T

Thermal ResistanceJunction-ambient Max. 80 100

=25°C; unlessotherwisenoted)

amb

C/W

°

Symb o l Parameter Test Cond itions Mi n . Typ . Max. Unit

V

I

SupplyVoltage 4.5 7 V

CC

QuiescentSupplyCurrent VCC=7V 25 mA

CC

COMPARATOR SECTION

Symb o l Parameter Test Cond itions Mi n . Typ . Max. Unit

V

V

I

I

Input Voltage Range V

IN

Input Offset Voltage VIN= 1.4V

IO

Input Offset Current

IO

Input Bias Current 1 µ

IB

Response time V

Inputs –0.3 3 V

sense

±5.0

±200

REF

= 1.4V V

= 0 to 5V 0.8 1.5

SENS

W
W

C

°
°C

mV

nA

µ

A

s

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L65 06 - L6506D

ELECTRICAL CHARACTERISTICS(continued)
COMPARATOR SECTIONPERFORMANCE(OverOperatingTemperatureRange)

Symbol Parameter Test Condtions Min. Typ. Max. Unit

V

Input Offset Voltage VIN= 1.4V

IO

Input Offset Curent

I

IO

±

±

500

20

mV

nA

LOGICSECTION

Symbol Parameter Test Condtions Min. Typ. Max. Unit

V

V

V

Input High Voltage 2 V

IH

Input Low Voltage 0.8 V

V

IL

Output High Voltage VCC= 4.75V

OH

Ouptut Low Voltage VCC= 4.75V

OL

Ouput Source Current - Outputs

I

OH

1-4

(OverOperatingTemperatureRange -TTL compatibleinputs& outputs)

2 3.5 V

= 400µA

I

OH

0.25 0.4 V

= 4mA

I

OH

VCC= 4.75V 2.75 mA

s

OSCILLATOR

Symbol Parameter Test Condtions Min. Typ. Max. Unit

f
V

V

Frequency Range 5 70 KHz

osc

Lower Threshold Voltage 0.33 V

thL

Higher Threshold Voltage 0.66 V

thH

Internal Discharge Resistor 0.7 1 1.3

R

i

CC
CC

CIRCUIT OP ERATION

TheL6506isintendedfor use withdual bridgedriv­ers,suchasthe L298,quaddarlingtonarrays,such
as the L7150, quad DMOS array such as L6114­L6115,ordiscretepowertransistorstodrivestepper
motorsandothersimilarloads.Themainfunctionof
thedeviceistosenseandcontrolthecurrentineach
of theload windings.

Acommonon-chiposcillatordrivesthedualchopper
andsetsthe operatingfrequencyforthepulsewidth
modulateddrive.The RCnetworkon pin1 setsthe
operatingfrequencywhichis givenby the equation
:

f = forR > 10 K

1

0.69 RC

The oscillator provides pulses to set the two flip­flopswhichin turncausethe outputsto activatethe
drive.Whenthecurrentintheloadwindingreaches
theprogrammedpeakvalue,thevoltageacrossthe
senseresistor (R

) is equal to V

sense

and the cor-

ref

respondingcomparatorresetsits flip-flopinterrupt­ingthedrivecurrentuntilthenextoscillatorpulseoc­curs. The peak current in each winding is pro­grammedby selectingthe valueofthe senseresis-

tor and V

. Sinceseparateinputsare providedfor

ref

each chopper, each of the loads may be pro­grammed independentlyallowing the device to be
used to implement microstepping of the motor.
LowerthresholdofL6506’soscillatoris 1/3V
per thresholdis 2/3 V

sistoris 1 KΩ ±

30%.

and internal dischargere-

CC

CC

Ground noise problems in multiple configurations
can be avoided by synchronizing the oscillators.
This may be done by connecting the sync pins of
eachof the deviceswith the oscillatoroutput of the
masterdeviceandconnectingtheR/Cpinoftheun­usedoscillatorsto ground.

Theequationsfor the activetime of thesync pulse
(T2),the inactivetimeof thesyncsignal(T1)andthe
dutycyclecanbefoundbylookingatthefigure1 and
are:

R1R

T2 = 0.69C1 (1)

R1 + R

IN

IN

T1 = 0.69 R1C1 (2)
DC= (3)

T2

T1 + T2

V

V
V

kΩ

.Up-

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