100V/5ASTEP AND MICROSTEPDRIVE BOARD
FEATURES
100V OperatingSupplyVoltage
5A/phasepeak current
5, 25, 125 microsteps/step
Fullstep and half step operation
User selectablephasecurrent
90° out of phase chopping to save power consumption
Galvanicisolation
Fulloutput protectionagainstshort-circuits
Thermaland undervoltageprotection
Step clock in excess of 200kHz
Fault indicationoutput
Special circuit to reduce midrangeinstability
GS-D500A
FOR STEPPER MOTORS
DESCRIPTION
The GS-D500Ais a member of the SGS-THOMSON family of stepper motor driver modules and
boards. It drives motors in full step, half step and
microstep mode.
On top of that if offers an unusually large number
of featuresthatallow a complete control of the
electromechanical characteristics of the motion
systemtoobtain optimumperformance.
The powermos output stages offer both low conductionandcommutationlosses for increasedefficiency; this, combined with a completeprotection
scheme, results in an extremely rugged unit suitable for harsh environmentoperation.
ABSOLUTE MAXIMUM RATINGS
Symbol Parameter Value Unit
V
s
V
ss
l
ph
l
i
V
is
T
stg
T
hop
Note: Absolute maximum ratings are limitvalues above which the unit can be permanently damaged
* Thermal protection intervention @ Th > 90°C
DC Supply Voltage
DC Logic Supply Voltage
Output Current per Bridge
Logic InputCurrent
Isolation Voltage
Storage Temperature Range
Operating Heatsink Temperature
110 V
13 V
6Apk
30 mA
500 V
– 20 to +85 °C
+85 °C
June 1994 1/10
GS-D500A
ELECTRICALCHARACTERISTICS (T
Symbol
V
V
I
V
I
* Output Shorts Protection phase-to-phase, phase-to-ground.
Note: the unitrequires an input filtering capacitor in the range of 4700 to 10000 µF/100V, with low ESR and locatedas close aspossible to the
board.
DC Supply Voltage
s
DC Logic Supply Voltage
ss
Phase Current per Output*
ph
Logic Input Current
l
i
On board Logic
sl
Supply Output
On board Logic
osl
Supply Current Output
Clock Pulse Frequency
f
c
Parameter Test Conditions Min Typ Max Unit
=25°C and Vs=24V unless otherwisespecified)
amb
12 100 V
11.5 12 12.5 V
0.5 5 A
4.75 5 5.25 V
10 mA
100 mA
200 kHz
Figure1. Signals timing
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Figure2. Block diagram
GS-D500A
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GS-D500A
MECHANICALDATA (dimensionsare in millimeters)
GS-D500AHARDWARE AVAILABLE COMMANDS
SW1, SW2, SW3
SW4
SW5
SW6
R42
R43
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Microsteps/step programming
Phase peak current selection
Midrange stabilization ON/OFF
Current reduction at rest
Phase AB current programming
Phase CD current programming
GS-D500A
GS-D500ACONNECTORS PINS DESCRIPTION
CONNECTOR J1
J1-1 PhaseA output
J1-2 PhaseB output
J1-3 PhaseC output
J1-4 PhaseD output
J1-6 Ground
CONNECTOR J2
J2-1 MotorSupply Voltage
J2-3 Auxiliary SupplyVoltage (+12V)
J2-2,4 Ground
CONNECTOR J3
Pin Function
J3-1 Stepclockisolated input(see fig. 3):this
is a logic input that performs the step
function, i.e. on every transition of this
input the motoris moved one step in the
proper direction.
J3-2 Direction isolated input (see fig. 4): the
logicstate appliedto thispin decidesthe
rotation direction of the motor shaft.
J3-4 Microsteps/step rate remote program-
ming(SW1).
J3-5 Onboard +5V output
J3-6,7 Return path for on board +5V output
J3-8 Disable input (see fig. 6): a logic high
level applied to this input causes the
powerdriver outputsto float. This condi-
tionallows the manual positioningof the
system.
Care must be used when this input is
activated because the detention torque
is lost.
J3-9 Optocouplersupply voltage
J3-10 Zero current control isolated input (see
fig. 5):when activatedthe phase current
is reduced to zero
J3-12 Microsteps/step rate remote program-
ming(SW2)
J3-13 Fault logic output (see fig.9): thisouput
is at a low logic level whenever an
anomalouscondition is detected.
J3-15 Microsteps/step rate remote program-
ming(SW3)
Figure 3. Stepclock inputcircuit Figure4. Direction input circuit
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GS-D500A
Figure5. Zero current input circuit Figure 6. Disable input circuit
A - GS-D500ADESCRIPTION
The GS-D500A is a complete subsystem to drive
steppermotorseitherinfullstepor microstepmode.
Averylarge numberof auxiliary functions hasbeen
includedtoallow extremesimplicity andflexibilityin
use.
Particularcarehas been devotedto protections,so
thattheGS-D500A canbesafelyusedin veryharsh
environments.
In additionto theobviousfunctiontodrivethe motor
phasesin a choppingmode, thefollowingfunctions
have been implemented:
- Sine/cosinegeneration
- Selectionofthreedifferentmicrosteps/steprates
- Selectionof full/halfstep drive
- Programmingofpeakphasecurrentto optimize
the torque
- Automatic phase current reduction at rest (selectable)
- Full protection against short-circuit between
phase-to-phaseand phase-to-ground
- Thermal and undervoltageprotection
- Galvanic isolation of 3 input signals (clock,
direction,zero current).
- Fault indicationoutput
- On boardauxiliary voltages generation
- Midrangestability circuitry (selectable)
As aresult, theGS-D500A canprovideup to5Aper
phase and, in its simplest application, just three
commandsignals are required: step clock, direc-
tion, disable.
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A1 - SUPPLY VOLTAGE
THE POWER SUPPLY MUST BE TURNED OFF WHEN
GS-D500A
PLUGGING OR UNPLUGGING THE BOARD
Thesupply pins are:
J2-1 for Motor SupplyVoltage
J2-3for AuxiliaryVoltage
J2-2,4 for Ground rail
The other supply voltages needed by the boards
are internallygenerated.
If an undervoltagecondition is detected (Vs < 10V)
the GS-D500Ais automaticallydisabled and a led
is activated.
TheMotor Supplyvoltageis in the rangefrom 12 to
100V,the Auxiliary voltage from 11 to 13V.
At power-on the Auxiliary Supply voltage must
be applied before the Motor Supply voltage,
while at power-off the Motor Supply voltage
must be removed before the Auxiliary voltage.
A2- FULL-STEP/HALF-STEP/MICROSTEPPROGRAMMINGBY HARDWARE
Thenumberof microstepsperstepisfieldprogrammable. The digitized sine and cosine functions,
requiredby a microstepping control,are stored in a
Lock-Up-Table inside the GS-D500A.
Two options are provided for the proper microsteps/steprate selection.
Threeswitches (SW1,SW2, SW3) areavailableon
the front edge of the board.
The full-step/half-step/microstep mode is defined
by the following table.
A2.1 - MICROSTEP PROGRAMMING BY HOST
COMPUTER
The microsteps/step rate can also be remotely
changed byusing the three logic inputs available
on the J3 connector (pins 4,12 and 15) that corresponds, respectively, to SW1, SW2, SW3.
Theinteractionbetweenlogicsignalsandhardware
switches is shown in fig. 4.
Figure 7. Remote microsteppingprogramming
SW1 SW2 SW3 MODE
OFF ON OFF
ON ON OFF
ON OFF ON
OFF ON ON
ON ON ON
Half step
125 microsteps/step
25 microsteps/step
5 microsteps/step
Full step
The switches are in OFF condition when the knob
is pulled versus the board edge. Invalid combinationsdisable the board.
To operate the logic pins of the J3 connector,the
three internalswitches must be in the OFF state.
A3 - CURRENT REDUCTION AT REST
Phase current can be reduced when the motor is
stopped if SW6 is open.
Current reductionis operative about1 second after
the lastclock pulse.
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GS-D500A
A4 - SETTING OF THE DIRECTIONPOLARITY
Therotation direction signalmust beapplied at pin
J3-3.
The direction(CW or CCW) dependson the status
of the direction signal as shown in the following
table:
DIR. SIGNAL ROTATION
HIGH CCW
LOW CW
A5 - PHASE CURRENT PROGRAMMING
The phase current can be programmed by means
two on-board trimmer called R42 and R43 (see
mechanicaldrawing).
R42 programs the current in phase AB,while R43
programsthe current in phase CD.
Figure8. Currentselection by SW4
A6 - MIDRANGESTABILITY
Aparticularcircuitry is implementedonthe boardto
avoid midrangeoscillations.
This circuit is inserted on the current control loop
when SW5 is OFF.
A7 - CURRE NT SEL EC TIO N IN MICROSTEP/CONSTANT CURRENT SWITCHING
(SW4)
When the board is used to drive a motor in microstepmode,an automaticswitchingfromsinusoidal/cosinusoidal current to constant current is
performed when the sinusoidal output waveform exceeds 500Hz. The constant outputcurrent can be chosen to b e 0.707 of the peak
current or the peak current: this possibility is
givenbySW4.(Seefig.8).
SW4 OFF 0.707 x Ipeak
SW4ON Ipeak
An histeresys isinsertedon the 500Hz thresholdto
avoid unwantedoscillations.
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GS-D500A
A8- OUTPUTOVERLOADAND SHORTCIRCUIT
PROTECTION
To prevent permanent damage to the GS-D500A,
three protections havebeen implemented against
overloadand short circuits between:
- outputto output
- outputto ground
Whenone ofthese adverseconditions occurs,the
driver of the output H-bridges is disabled for about
500msand the condition is signaledby the FAULT
signal.
Figure9 - FAULT signal output circuit
A9 - FAULT SIGNAL
The FAULTsignal isavailableat pin J3-13.When a
fault is present, pin13 goes low versus pins 6,7.
Whenever the FAULT signal is activated, the led
providedin thefront edgeofthe moduleisswitched
ON.
The FAULTsignal is active (low) when:
- the supply voltageis lower than 12V
- the heatsink temperatureis higher than 90°C
- an output overload ispresent
- a disable is active.
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GS-D500A
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. Specification mentioned
in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied.
SGS-THOMSON Microelectronics productsare not authorized for use as critical components inlife supportdevices or systems withoutexpress
written approval of SGS-THOMSON Microelectronics.
1994 SGS-THOMSON Microelectronics – All Rights Reserved
Australia - Brazil - China - France- Germany - Hong Kong - Italy - Japan - Korea - Malaysia - Malta - Morocco - The Netherlands -
Singapore - Spain - Sweden - Switzerland - Taiwan- Thailand -United Kingdom - U.S.A.
SGS-THOMSON Microelectronics GROUP OF COMPANIES
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