Datasheet TEA3718SFP, TEA3718SP, TEA3718SDP, TEA3718DP Datasheet (SGS Thomson Microelectronics)

TEA3 718

TEA3718S

STEPPER MOTOR DRIVER

ADVANCE DATA

HALF-STEPAND FULL-STEPMODE
BIPOLARDRIVE OF STEPPERMOTOR FOR
MAXIMUM MOTORPERFORMANCE
BUILT-INPROTECTIONDIODES
WIDERANGEOF CURRENT CONTROL5 TO
1500mA
WIDEVOLTAGERANGE10 TO 50 V
DESIGNED FOR UNSTABILIZED MOTOR
SUPPLYVOLTAGE
CURRENT LEVELS CAN BE SELECTED IN
STEPSOR VARIEDCONTINUOUSLY
THERMALOVERLOADPROTECTION
ALARM OUTPUT OR PRE-ALARM OUTPUT
(seeinternaltable)

DESCRIP T IO N

TheTEA3718andTEA3718Sarebipolarmonolithic
integratedcircuitsintended to control and drive the
currentin one winding of a bipolar stepper motor.
The circuits consist of an LS-TTL compatiblelogic
input,a currentsensor,amonostableandanoutput
stagewith built-inprotectiondiodes.TwoTEA3718
or TEA3718Sand a few externalcomponentsform
a complete control and drive unit for LS-TTLor mi­croprocessor-controlledsteppermotor systems.

Powerdip

12+2+2

ORDERINGNUMBERS :

TEA3718SDP
TEA3718DP

MULTIWATT-15

ORDERING NUMBER : TEA3718SP

SO-20

ORDERING NUMBER :

TEA3718SFP

PIN CONNECTI O NS (top views)

TEA3718SP

(Multiwa tt -1 5)

December 1991

Thisis advanced informationon a new product now in development or undergoing evaluation. Details are subject to change withoutnotice.

TEA3718SFP

(SO-20)

TEA3718DP

TEA3718SDP

(Powerdip 12+2+2)

1/16

TEA371 8-TEA 3718S

BLOCK DIAGRAM TEA3718S

BLOCK DIAGRAM TEA3718

2/16

TEA3718- TEA3718S

PIN FUNCTIONS

Name Function

OUT B Output Connection (with pin OUTA). The output stage is a ”H” bridge formed by four

transistors and four diodes suitable for switching applications.

PULSE TIME A parallel RC network connected to this pin sets the OFF time of the lower power

transistors. The pulse generator is a monostable triggered by the rising edge of the
output of the comparators (t

(B) Supply Voltage Input for Half Output Stage

V

S

GND Ground Connection. In SO-20L and Powerdip these pins also conduct heat from die

to printed circuit copper.

V

SS

Supply Voltage Input for Logic Circuitry

IN1 This pin and pin IN0 are logic inputs which select the outputs of three comparators to

set the current level. Current also depends on the sensing resistor and reference
voltage. See truth table.

PHASE This TTL-compatible logic input sets the direction of current flow through the load. A

high level causes current to flow from OUT A (source) to OUT B (sink). A Schmitt
trigger on this input provides good noise immunity and a delay circuit prevents output
stage short circuits during switching.

IN0 See INPUT 1

COMPARATOR INPUT Input connected to the three comparators. The voltage across the sense resistor is

feedback to this input through the low pass filter R
are disabled when the sense voltage exceeds the reference voltage of the selected
comparator. When this occurs the current decays for a time set by R

.

R

TCT

REFERENCE A voltage applied to this pin sets the reference voltage of the three comparators.

Reference voltage with the value of R
the output current.

(A) Supply voltage input for half output stage

V

S

OUT A See pin OUT B

SENSE RESISTOR Connection to lower emitters of output stage for insertion of current sense resistor

ALARM When T

PRE-ALARM When T

reaches T1°C the alarm output becomes low (TEA3718SP)

j

reaches T2°C the prealarm output becomes low (T2<T1) (TEA3718SFP)

j

= 0.69 RTCT).

off

. The lower power transistor

CCC

TCT,Toff

and the two inputs IN0 and IN1 determines

S

= 0.69

3/16

TEA371 8-TEA 3718S

ABSOLUTE MAXIMUM RATINGS

Symbol Parameters Value Unit

V

T

THERMAL DAT A

Symbol Parameter SO-20L Powerdip Multiwatt Unit

R

R

*

Solderedon a 35 µm thick4 cm

Supply Voltage 7

SS

V

S

Input Voltage:

V

I

Logic Inputs
Analog Inputs
Reference Input

Input Current

i

i

Logic Inputs
Analog Inputs

Output Current ±1.5 A

I

O

Junction Temperature +150 °C

T

J

Operating Ambient Temperature Range 0 to 70 °C

T

op

Storage Temperature Range -55 to +150 °C

stg

(j-c) Maximum Junction-case Thermal Resistance 16 11 3

th

(j-a) Maximum Junction-ambient Thermal Resistance 60 * 45 * 40

th

2

PC boardcopper area.

50

V

15

-10

-10

6

SS

°C/W
°C/W

V
V

V
V
V

mA
mA

RECOMMENDED OPERATING CONDITIONS

Symbol Parameter Min. Typ. Max. Unit

v
V

i

m

T

amb

t
t

Supply Voltage 4.75 5 5.25 V

ss

Supply Voltage 10 – 45 V

S

Output Current 0.020 – 1.2 A
Ambient Temperature 0 70 °C
Rise Time Logic Inputs – – 2 µs

r

Fall Time Logic Inputs – – 2 µs

f

COMPARISON TABLE

Device Curren t P ackag e Alarm Pre-Alarm

TEA3718SDP 1.5A Powerdip 12+2+2 not connected

TEA3718SFP 1.5A SO-20L x

TEA3718SP 1.5A Multiwatt-15 X
TEA3718DP 1.5A Powerdip 12+2+2 not connected

4/16

MAXIMUM POWER DISSIPATION

TEA3718- TEA3718S

Figure 1.

Figure 2.

RS=1 Ω INDUCTANCEFREE
R

= 470 Ω

C

C

= 820pF CERAMIC

C

R

=56kΩ

t

C

= 820 pF CERAMIC

t

P = 500 Ω
R

=1K

2

5/16

TEA371 8-TEA 3718S

ELECTRICAL CHARACTERISTICS (VCC= 5V, ± 5%, Vmm= 10V to 45V, T

=25°C for TEA3718FP/SFP)unless otherwise specified)

(T

amb

= 0 to 70°C

amb

Symbol Parame t er Min. Typ. Max. Unit

Supply Current - - 25 mA

I

CC

High Level Input Voltage - Logic Inputs 2 - - V

V

IH

Low Level Input Voltage - Logic Inputs - - 0.8 V

V

IL

High Level Input Current - Logic Inputs - - 20 µA

I

IH

Low Level Input Current - Logic Inputs (VI = 0.4V) -0.4 - - mA

I

IL

V

CH

V

CM

V

CL

I

CO

I

off

V

sat

P

tot

t

off

t

d

V

sat

I

ref

V

sat

Comparator Thershold Voltage (VR = 5V) IO=0

=0

I

O

=0

I

O

I

=0

1

=0

I

1

=1

I

1

Comparator Input Current -20 - 20 µA
Output Leakage Current (IO=0, I1=1T

=25°C - - 100 µA

amb

Total Saturation Voltage Drop (Im = 1A) SO20/Powerdip

Multiwatt
Total Power Disssipation - Im= 1A, fs= 30KHz - 3.1 3.6 W
Cut off Time (see figure 1 and 2, Vmm= 10V, V
Turn off Delay (see fig. 1 and 2, T

=25°C, dVC/dt>50mV/µs) - 1.6 - µs

amb

>5µs 253035ms

ton

Alarm Output Saturation Voltage - IO= 2mA (Multiwatt) - 0.8 - V
Reference Input Current, VR= 5V - 0.4 1 mA
Source Diode Transistor Pair Saturation

Voltage

Powerdip Im= 0.5A

Powerdip I

m

=1A

390
230

65

-

-

-

-

420
250

80

-

-

1.05

1.35

440
270

90

2.8

3.2

1.2 (1.3)

1.5 (1.7)

mV
mV
mV

V
V

V
V

Diode Forward Voltage If= 0.5A

V

f

Substrate Leakage Current If=1A - - 5 mA

I

sub

V

Sink Diode Transistor Pair Saturation

sat

Voltage

Diode Forward Voltage If= 0.5A

V

f

Notes:
(...) Only for TEA3718SFP mounted in SO-20L package.

Multiwatt I

Multiwatt I

= 0.5A

m

m

I

f

=1A

=1A

Powerdip Im= 0.5A

Powerdip I

Multiwatt I

Multiwatt I

=1A

m

= 0.5A

m

m

=1A

I

f

=1A

-

-

-

-

-

-

-

-

-

-

-

-

1.1

1.25

1

1.2

-

-

1

1.1

1.3

1.7

1.5 (1.6)

1.7 (1.9)

1.2 (1.3)

1.3 (1.5)

1.3

1.5

1.4 (1.6)

1.5 (1.9)

V
V

V
V

V
V

V
V

V
V

6/16

TEA3718- TEA3718S

7/16

TEA371 8-TEA 3718S

FUNCTIONAL BLOCKS
Figure A: ALARM OUTPUT (TEA3718SP - TEA3718DP)

TEA3718

Figure B: PRE-ALARMOUTPUT (TEA3718SDP- TEA3718SFP)

TEA3718S

8/16

TEA3718- TEA3718S

ALARM OUTPUTS (TEA3718SP- TEA3718DP)

The alarm output becomes low when the junc­tion temperature reaches T°C.
When an alarm condition occours, parts of the
supply voltage (dividing bridge R - R

) is fed to

C

the comparator input pin (Fig. A)
Depending of the R

C value the behaviour of

C

the circuit is different on alarm condition:

>80Ω⇒the output stage is switched off

1) R

C

>60Ω⇒the current in the motor windings

2) R

C

is reduced according to the approximate formula:
(see also fig. E and F)

V

=

I

m

R

TH

V

−

R + R

S

CC

R

C

•

R

C

S

Figure C: Alarm Detection for Powerdip Package

with V
V

CM,VCL

= Threshold of the comparator (VCH,

TH

) R = 700Ω (typical)

For several Multiwatt packages a common de­tection can be obtained as in Fig. D

PRE-ALARM OUTPUT

When the junction temperature reaches T1°C
(typ. = 170°C) a prealarm signal is generated.

Soft thermal protection occours when function
temperaturereaches T2 (T2 > T1)

Figure D: CommonDetectionfor Several Multiwatt Package

9/16

TEA371 8-TEA 3718S

Figure E: (typical curve) Current Reduction in

the Motor on Alarm Condition.

Notes: 1. Resistance values given here are for the Vchthreshold. They should be adjusted using other comparators threshold or other

V

value.

ref

Figure F: (V

rent on Alarm Condition.

5V) Block Diagram for Half Cur-

ref

TYPI CAL APP LI CAT IO N

10/16

Phase A

IN0A
IN1A

Phase B

IN0B
IN1B

FUNCTIO NAL DE S CRIPTIO N

The circuitisintended todrive a bipolarconstantcur­rentthroughonemotorwinding.Theconstantcurrent
is generatedthroughswitc h moderegulation.

Thereisachoiceofthreedifferentcurrentlevelswith
the two logic inputs lN0 and lN1. The current can
also beswitchedoff completely.

INPUTLOGIC
If any of the logic inputsis left open, the circuitwill

treatit asa high levelinput.

IN0 IN1 Current Level

H

H

No Current

L

H

Low Current

H

L

Medium Current

L

L

Maximum Current

PHASE- Thisinputdeterminesthedirectionof cur­rent flow in the winding, depending on the motor
connections.The signal is fed through a Schmidt­triggerfor noiseimmunity,andthrougha timedelay
in order to guaranteethat no short-circuitoccurs in
the output stage during phase-shift. High level on
thePHASEinputcausesthemotorcurrentflowfrom
Out A through thewindingto Out B.

andlH1- The currentlevel in the motor winding

l

H0

is selectedwith these inputs.The valuesof the dif­ferent current levels are determined by the refer­encevoltageV
ing resistor R

togetherwiththevalueofthesens-

R

.

S

CURRENTSENSOR
Thispart containsa currentsensingresistor (RS),a

lowpassfilter(R

) andthreecomparators.Only

C,CC

one comparatorisactiveat a time. It isactivatedby
the inputlogicaccordingtothe currentlevelchosen
with signals IN0 and IN1. The motor current flows
throughthe sensingresistor R
has increased so that the voltage across R

. Whenthe current

S

S

be­comes higher than the reference voltage on the
othercomparatorinput,thecomparatoroutputgoes
high,whichtriggersthe pulsegeneratorandits out­put goes high during a fixed pulse time (t

), thus

off

switching off the power feed to the motor winding,
and causing the motor current to decreaseduring

.

t

off

TEA3718- TEA3718S

Thesinglepulse switchesoff the powerfeed to the
motor winding, causing the winding current to de­creaseduringt

If a new trigger signal should occur during t
ignored.

OUTPUT STAGE
The output stage contains four Darlington transis-

torsandfourdiodes,connectedin anH-bridge.The
twosinkingtransistorsare usedto switchthe power
suppliedto the motor winding, thus driving a con­stant current through thewinding.

It should be noted however, that it isnot permitted
toshort circuit the outputs.

V

SS,VS,VR

Thecircuit will stand anyorder of turn-onor turn-off
the supply voltages V
uesare then assumed.

Preferably,V
onand power-offif V

ANALOGCONTROL
Thecurrentlevelscan bevaried continuouslyif V

is varied with a circuit varying the voltage on the
comparatorterminal.

POWER LOSSES V

.

off

off

and VS. Normal dV/dt val-

SS

shouldbetrackingVSSduringpower-

R

isestablished.

S

OUTPUT CURRE NT

S

,itis

R

SINGLE-PULSEGENERATOR
The pulse generator is a monostabletriggered on

the positive going edge of the comparator output.
Themonostableoutputishighduringthepulsetime,

, which is determinedby the timingcomponents

t

off

andCt.

R

t

t

= 0.69 ⋅ RtC

off

t

11/16

TEA371 8-TEA 3718S

PRINCIPAL OPERATING SEQUENCE

APPLICATION NOTES

MOTOR SELECTION
Somesteppermotorsare notdesignedfor continu-

ous operation at maximum current. As the circuit
drivesa constantcurrentthroughthemotor,its tem­peraturemightincreaseexceedinglybothatlowand
high speed operation.

Also, some stepper motors have such high core
lossesthattheyare not suitedfor switchmode cur­rentregulation.

UNUSED INPUTS
Unusedinputsshouldbeconnectedtopropervoltage

levelsin orderto get the highestnoise imm unity .

12/16

INTERFERENCE
As the circuit operates with switch mode current

regulation,interferencegenerationproblemsmight
arise in some applications. A good measuremight
thenbeto decouplethecircuitwith a 15 nF ceramic
capacitor,locatednearthepackagebetweenpower
line V

The ground leadbetween R

andground.

S

and circuit GND

S,CC

should be kept as short as possible. This applies
alsototheleadbetweenthesensingresistorR

S

and

pointS, see FUNCTIONAL BLOCKS.

MULTIWATT15 PACKAGE MECHANICAL DATA

TEA3718- TEA3718S

DIM.

MIN. TYP. MAX. MIN. TYP. MAX.

A 5 0.197
B 2.65 0.104
C 1.6 0.063
D 1 0.039
E 0.49 0.55 0.019 0.022
F 0.66 0.75 0.026 0.030
G 1.02 1.27 1.52 0.040 0.050 0.060

G1 17.53 17.78 18.03 0.690 0.700 0.710

H1 19.6 0.772
H2 20.2 0.795

L 21.9 22.2 22.5 0.862 0.874 0.886
L1 21.7 22.1 22.5 0.854 0.870 0.886
L2 17.65 18.1 0.695 0.713
L3 17.25 17.5 17.75 0.679 0.689 0.699
L4 10.3 10.7 10.9 0.406 0.421 0.429
L7 2.65 2.9 0.104 0.114

M 4.25 4.55 4.85 0.167 0.179 0.191

M1 4.63 5.08 5.53 0.182 0.200 0.218

S 1.9 2.6 0.075 0.102

S1 1.9 2.6 0.075 0.102

Dia1 3.65 3.85 0.144 0.152

mm inch

13/16

TEA371 8-TEA 3718S

POWERDIP16 PACKAGE MECHANICAL DATA

DIM.

MIN. TYP. MAX. MIN. TYP. MAX.

a1 0.51 0.020

B 0.85 1.40 0.033 0.055

b 0.50 0.020

b1 0.38 0.50 0.015 0.020

D 20.0 0.787

E 8.80 0.346

e 2.54 0.100

e3 17.78 0.700

F 7.10 0.280

I 5.10 0.201

L 3.30 0.130

Z 1.27 0.050

mm inch

14/16

SO20 PACKAGE MECHANICAL DATA

TEA3718- TEA3718S

DIM.

MIN. TYP. MAX. MIN. TYP. MAX.

A 2.65 0.104
a1 0.1 0.3 0.004 0.012
a2 2.45 0.096

b 0.35 0.49 0.014 0.019
b1 0.23 0.32 0.009 0.013

C 0.5 0.020

c1 45 (typ.)

D 12.6 13.0 0.496 0.512

E 10 10.65 0.394 0.419

e 1.27 0.050
e3 11.43 0.450

F 7.4 7.6 0.291 0.299

L 0.5 1.27 0.020 0.050

M 0.75 0.030

mm inch

S 8 (max.)

15/16

TEA371 8-TEA 3718S

Information furnished is believed to be accurate and reliable. However, SGS-THOMSON Microelectronics assumes no responsibility for
the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its
use. No license is granted by implication or otherwise under any patent or patent rights of SGS-THOMSON Microelectronics. Specifica­tions mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information pre­viously supplied. SGS-THOMSON Microelectronics products are not authorized for use as critical components in life support devices or
systems without express written approval of SGS-THOMSON Microelectronics.

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