IMS IM483 User manual

intelligent motion systems, inc.
Excellence in MotionTM
IM483
HIGH PERFORMANCE MICROSTEPPING DRIVE
STANDARD DRIVER
CONNECTOR OPTIONS
DUAL STEP CLOCK INPUT VERSION
COOLING SOLUTIONS
ACCESSORIES
OPERATING INSTRUCTIONS
TM
370 N. MAIN ST., PO BOX 457, MARLBOROUGH, CT 06447
PH. [phone], FAX [phone]
Internet: http://www.imshome.com, E-Mail: [email protected]
TM

© Intelligent Motion Systems, Inc.
All Rights Reserved
IM483 Operating Instructions
Revision R032306
The information in this book has been carefully checked and is believed to be
accurate; however, no responsibility is assumed for inaccuracies.
Intelligent Motion Systems, Inc., reserves the right to make changes without
further notice to any products herein to improve reliability, function or design.
Intelligent Motion Systems, Inc., does not assume any liability arising out of
the application or use of any product or circuit described herein; neither does it
convey any license under its patent rights of others. Intelligent Motion Systems
and are trademarks of Intelligent Motion Systems, Inc.
Intelligent Motion Systems, Inc.’s general policy does not recommend the use of
its products in life support or aircraft applications wherein a failure or malfunction
of the product may directly threaten life or injury. Per Intelligent Motion Systems,
Inc.’s terms and conditions of sales, the user of Intelligent Motion Systems, Inc.,
products in life support or aircraft applications assumes all risks of such use and
indemnies Intelligent Motion Systems, Inc., against all damages.

Change Log
Date Revision Changes
03/23/2006 R032306 Updated IMS Contact info, warranty and disclaimer info on cover. Up-
dated recommended IMS Motor Part Numbers.

1IM483 Operating Instructions Revision R032306
Table of Contents
Introduction............................................................................................... 5
The IM483 ..................................................................................................................... 5
Features and Benets ................................................................................................... 5
The Product Manual ...................................................................................................... 6
The Product Manual ...................................................................................................... 6
Notes and Warnings...................................................................................................... 7
Hardware Specications........................................................................... 8
Section Overview .......................................................................................................... 8
Mechanical Specications ............................................................................................. 8
Electrical Specications................................................................................................. 9
Thermal Specications ................................................................................................ 10
Pin Assignment and Description ................................................................................. 10
Mounting The IM483 .............................................................................. 13
Theory of Operation ............................................................................... 14
Section Overview ........................................................................................................ 14
Circuit Operation ......................................................................................................... 14
Microstep Select (MSEL) Inputs.................................................................................. 15
Stepping ...................................................................................................................... 15
Dual PWM Circuit ........................................................................................................ 16
Fullstep Output Signal ................................................................................................. 17
Timing.......................................................................................................................... 17
Power Supply Requirements.................................................................. 18
Section Overview ........................................................................................................ 18
Selecting a Power Supply ........................................................................................... 18
Selecting an Opto Supply............................................................................................ 20
Recommended Wiring................................................................................................. 21
AC Line Filtering.......................................................................................................... 22
Motor Requirements............................................................................... 23
Section Overview ........................................................................................................ 23
Selecting a Motor ........................................................................................................ 23
Motor Wiring ................................................................................................................ 28
Connecting the Motor .................................................................................................. 28
Interfacing and Controlling the IM483 .................................................... 32
Section Overview ........................................................................................................ 32
Layout and Interface Guidelines.................................................................................. 32
Motor Power Connection (+V)..................................................................................... 33
Conguring and Controlling the Output Current .......................................................... 34
Controlling the Output Resolution ............................................................................... 39
Interfacing and Using the Isolated Logic Inputs .......................................................... 41
Connecting and Using the Fault Output ...................................................................... 47
Full Step Output .......................................................................................................... 48
Minimum Connections................................................................................................. 49
Troubleshooting...................................................................................... 50
Section Overview ........................................................................................................ 50
Basic Troubleshooting................................................................................................. 50
Problem Symptoms and Possible Causes .................................................................. 50
Contacting Technical Support ..................................................................................... 53
The IMS Web Site ....................................................................................................... 53
Returning Your Product to IMS ................................................................................... 53

2 IM483 Operating Instructions Revision R032306
3IM483 Operating Instructions Revision R032306
Appendix A: Standard Connection Options............................................ 54
Appendix Overview ..................................................................................................... 54
IM483-34P1................................................................................................................. 55
IM483-8P2................................................................................................................... 60
IM483-34P1-8P2 ......................................................................................................... 62
IM483-PLG .................................................................................................................. 64
Appendix B: Input Options...................................................................... 66
IM483-DC .................................................................................................................... 66
Appendix C: Cooling Solutions............................................................... 68
H-4X Heat Sink Kit ...................................................................................................... 68
Thermal Non-Isolating Pad (TN-48) ........................................................................... 68
Appendix D: Accessories ....................................................................... 69
Appendix Overview ..................................................................................................... 69
U3-CLP: Side-Mounting Clip ....................................................................................... 69
BB-34-4P Breakout Board........................................................................................... 71
PLG-R Removable Screw Terminal Set...................................................................... 73
Appendix E: Recommended Cable Congurations ................................ 74

2 IM483 Operating Instructions Revision R032306
3IM483 Operating Instructions Revision R032306
List Of Figures
Figure 2.1 IM483 Dimensions .................................................................................. 8
Figure 2.2 IM483 Pin Conguration ....................................................................... 10
Figure 3.1 Mounting Recommendations ................................................................ 13
Figure 4.1 IM483 Block Diagram ........................................................................... 14
Figure 4.2 Recirculating PWM ............................................................................... 16
Figure 4.3 Non-Recirculating PWM ....................................................................... 16
Figure 6.1 Per Phase Winding Inductance ............................................................ 25
Figure 6.2 8 Lead Motor Series Connections ........................................................ 29
Figure 6.3 8 Lead Motor Parallel Connections....................................................... 29
Figure 6.4 6 Lead Motor Half Coil (Higher Speed) Connections ........................... 30
Figure 6.5 6 Lead Motor Full Coil (Higher Torque) Connections ........................... 30
Figure 6.6 4 Lead Motor Connections.................................................................... 31
Figure 7.1 IM483 Motor Power Connections ......................................................... 34
Figure 7.2 Current Adjust Resistor Placement....................................................... 37
Figure 7.3 Current Reduction Adjust Resistor Placement ..................................... 38
Figure 7.4 MSEL Switch Showing 50 Microsteps/Step Selected........................... 39
Figure 7.5 Optically Isolated Inputs........................................................................ 41
Figure 7.6 Switch Interface .................................................................................... 44
Figure 7.7 Open Collector Interface....................................................................... 45
Figure 7.8 TTL Interface ........................................................................................ 45
Figure 7.9 LYNX Interface ..................................................................................... 46
Figure 7.10 The Fault Output Connected to an LED ............................................... 47
Figure 7.11 The Full Step Output Connected to an Up/Down Counter ................... 48
Figure 7.12 IM483 Minimum Required Connections................................................ 49
Figure A.1 IM483-34P1 Connector P1 Mechanical Drawing.................................. 55
Figure A.2 IM483-34P1 Connector P1 Pin Locations ............................................ 55
FIgure A.3 MSEL Connection Using TTL Interface ................................................ 58
Figure A.4 Cascading IM483-34P1 Drives Using the Step/Direction Outputs ....... 59
Figure A.5 IM483-8P2 - Connector P1 ................................................................... 60
Figure A.6 IM483-8P2 - Connector P2 ................................................................... 60
Figure A.7 IM483-8P2 PCB Hole Pattern............................................................... 61
Figure A.8 IM483-34P1-8P2 - Connector P1 ......................................................... 62
Figure A.9 IM483-34P1-8P2 - Connector P2 ......................................................... 62
Figure A.10 IM483-34P1-8P2 PCB Hole Pattern ..................................................... 63
Figure A.11 IM483-PLG Connectors ........................................................................ 64
Figure A.12 IM483-PLG Pin Location and Orientation............................................. 65
Figure B.1 IM483-DC Connection .......................................................................... 67
Figure C.1 H-4X Heat Sink ..................................................................................... 68
Figure D.1 U3-CLP Mounting Hole Locations ........................................................ 69
Figure D.2 Attaching the U3-CLP to the IM483 ...................................................... 70
Figure D.3 Panal Mounting an IM483 Using the U3-CLP Clip Set ......................... 70
Figure D.4 BB-34-4P Breakout Board Mechanical Specications.......................... 71
Figure D.5 BB-34-4P Pin Locations........................................................................ 72
Figure D.6 BB-34-4P Mounting Diagram................................................................ 72

4 IM483 Operating Instructions Revision R032306
5IM483 Operating Instructions Revision R032306
List Of Tables
Table 2.1 Electrical Specications .......................................................................... 9
Table 2.2 IM483 Thermal Specications .............................................................. 10
Table 2.3 Connector P1 - Pin Assignment and Description.................................. 11
Table 2.4 Connector P2 - Pin Assignment and Description.................................. 12
Table 5.1 Motor Power Supply Requirements ...................................................... 19
Table 5.2 +5 VDC Power Supply Requirements .................................................. 20
Table 7.1 Current Adjust Resistor Values............................................................. 37
Table 7.2 Microstep Resolution Switch Settings................................................... 40
Table 7.3 Recommended Input Current Limiting Resistor Values........................ 42
Table 7.4 Isolated Logic Input Timing................................................................... 43
Table A.1 IM483-34P1 - Connector P1 Pin Assignment and Description ............ 56
Table B.1 IM483-DC - Connector P1 Pin Assignment and Description ................ 66

4 IM483 Operating Instructions Revision R032306
5IM483 Operating Instructions Revision R032306
Features and Benefits
n Low Cost.
n Small Size 2.75” x 3.00” x 1.20”
(69.9 x 76.2 x 30.5 mm).
n Advanced Surface Mount and ASIC Technology.
n High Input Voltage (+12 to +48VDC).
n High Output Current (3A RMS, 4A Peak).
n No Minimum Inductance.
Section 1
Introduction
The IM483
The IM483 is a high performance, yet low cost microstepping
driver that utilizes surface
mount ASIC technology. The
IM483 is small, easy to interface
and use, yet powerful enough
to handle the most demanding
applications.
The IM483 has 14 built-in mic-
rostep resolutions (both binary
and decimal). The resolution can
be changed at any time without
the need to reset the driver. This
feature allows the user to rapidly
move long distances, yet precisely position the motor at the end of travel
without the expense of high performance controllers.
With the development of proprietary and patented circuits, ripple current
has been minimized to reduce motor heating common with other de-
signs, allowing the use of low inductance motors to improve high speed
performance and system efciency.
The IM483, because of its small size and low cost, can be used to
increase accuracy and smoothness in systems using higher step angle
motors. In many instances mechanical gearing can be replaced with mic-
rostepping, reducing cost and eliminating potential maintenance.
Available as options for the IM483 are a variety of connector styles, a heat
sink and thermal pad and a dual clock input version of the IM483. If in-
telligent and/or closed loop control is needed the IM483 is available with
on-board indexer (IM483I) and indexer/encoder (IM483IE) versions.
The IM483 was developed to provide designers with affordable, state-of-the-art
technology for the competitive edge needed in today’s market.

6 IM483 Operating Instructions Revision R032306
7IM483 Operating Instructions Revision R032306
n FAULT Output.
n Optically Isolated Inputs.
n Single Supply.
n Up to 10MHz Step Clock Rate.
n Short Circuit and Over Temperature Protection.
n Microstep Resolution to 51,200 Steps/Rev.
n Microstep Resolutions can be Changed “On-The-Fly” With-
out Loss of Motor Position.
n 20 kHz Chopping Rate.
n Automatically Switches Between Slow and Fast Decay for
Unmatched Performance.
n 14 Selectable Resolutions Both in Decimal and Binary.
n Adjustable Automatic Current Reduction.
n At Full Step Output.
n Optional On-board Indexer and Encoder Feedback.
n CE Certied.
The Product Manual
The main sections of this manual address the standard IM483 driver,
which come with 8 position screw terminals as a connection medium.
The different connector, input options and accessories are covered in
detail in the appendices.
The indexer (IM483I) and indexer/encoder (IM483IE) versions of the
IM483 are not covered in this document, as they have their own manual.
The Product Manual
The IM483 product manual in its electronic format may be downloaded
from the IMS website at http://www.imshome.com. This version includes
a Bookmark feature that allows the reader to link from a Bookmarked
Topic in the Table of Contents to a full description of
that feature’s attributes and functions. You can also
select a Topic directly from the Table of Contents Pages.
Topics with a Bookmark function are further identiable
because the cursor changes from a normal pointer to a
“nger” pointer when placed over the word.

6 IM483 Operating Instructions Revision R032306
7IM483 Operating Instructions Revision R032306
WARNING! The IM483 components are sensitive to ElectroStatic
Discharge (ESD). All handling should be done at an ESD protected
workstation.
WARNING! Hazardous voltage levels may be present if using an
open frame power supply to power the IM483.
WARNING! Ensure that the power supply output voltage does not
exceed the maximum input voltage of the IM483.
Notes and Warnings

8 IM483 Operating Instructions Revision R032306
9IM483 Operating Instructions Revision R032306
12345678
0.150
(3.8)
2.45
(62.23)
2.750
(69.9)
1.00
(25.4)
0.312
(7.92)
0.290
(7.4)
2.710
(68.8)
3.00
(76.2)
0.030
(0.8)
4X Ø 0.160
(4X Ø 4.1)
1.20
(30.50)
0.410
(10.4)
1734
1
0.025
(0.6)
18
IM483-34P1
Section 2
Hardware Specifications
Section Overview
This section will acquaint you with the dimensional information, pin de-
scription, power, environmental and thermal requirements of the IM483.
It is broken down as follows:
n Mechanical Specications.
n Electrical Specications.
n Thermal Specications.
n Pin Assignment and Description.
Mechanical Specifications
Shown is the standard 8 position screw terminal set for the IM483.
Dimensions and specications for the different connection options are
available in Appendix A: Standard Connection Options, of this document.
Dimensions are in inches, parenthesis dimensions are in millimeters.
Figure 2.1: IM483 Dimensions

8 IM483 Operating Instructions Revision R032306
9IM483 Operating Instructions Revision R032306
Electrical Specifications
Test Condition: TA=25°C, +V=48VDC
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noitacificepS
noitidnoCtseT
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tinU
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SMR
**4.0 3
A
tnerruCtuptuOesahP kaeP 4 A
tnerruCtnecseiuQ
gnitaolFstuptuO/stupnI 07
Am
noitapissiDrewoPevitcA I
TUO
SMRA3= 21 W
tnerruCdrawroFtupnI
stupnIdetalosI
0.7 51
Am
egatloVdrawroFtupnI stupnIdetalosI 5.1 7.1 V
nwodkaerBesreveRtupnI
egatloV
stupnIdetalosI
5
V
tnerruCtuptuO stuptuOpetslluF,tluaF 52 Am
egatloVrettimE-rotcelloC
tuptuOtluaF
041
V
noitarutaSrettimE-rotcelloC
egatloV
tuptuOtluaF
I
SC
CDAm52= 2.0 V
egatloVecruoS-niarD
tuptuOpetslluF
001
V
ecnatsiseRnOecruoS-niarD tuptuOpetslluF
I
SC
CDAm52= 5.6 Ω
Table 2.1: IM483 Electrical Specications
* Includes motor back EMF.
**Lower currents may be used for current reduction.

10 IM483 Operating Instructions Revision R032306
11IM483 Operating Instructions Revision R032306
Thermal Specifications
)C°(snoitacificepSlamrehT384MI
noitacificepS egnaR
erutarepmeTtneibmA °05+ot°0
erutarepmeTegarotS °521+ot°04-
erutarepmeTetalPmumixaM °07+
Table 2.2: IM483 Thermal Specications
NOTE! Additional cooling may be required to limit the plate
temperature to 70°C! An optional heat sink and thermal pad is
available, see Appendix C: Cooling Solutions for details.
Pin Assignment and Description
Figure 2.2: IM483 Pin Conguration
NOTE! This pin conguration diagram and table represent
the pinout of any 8 position connector used for P1. If you
purchased the IM483-34P1 option (34 Position Header) the
pin conguration diagram and table is located in Appendix A:
Standard Connection Options.
MSEL0
MSEL1
MSEL2
MSEL3
ON
SW1
P1 P2
N/C - P1:1
Step Clock - P1:2
Direction - P1:3
Opto Supply - P1:4
Enable - P1:5
Reset - P1:6
Fault Output - P1:7
On-Full-Step Output - P1:8
P2:8 - Motor Ø A
P2:7 - Motor Ø
P2:6 - Motor Ø B
P2:5 - Motor Ø
P2:4 - +V (+12 to +48 VDC)
P2:3 - Ground
P2:2 - Current Adjust
P2:1 - Current Reduction Adjust
A
B

10 IM483 Operating Instructions Revision R032306
11IM483 Operating Instructions Revision R032306
Connector P1
Table 2.3: Connector P1 - Pin Assignment and Descriptions
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tnednepedsitnemercniehtfoezisehT.tnemercnieno
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fonoitcennocehtnopusdnepedoslanoitceridlacisyhP
.sgnidniwrotomeht
4ylppuSotpO
detalosiehtotrewopylppusotdesusitupniCDV5+sihT
tsumeractub,desuebyamegatlovrehgihA.stupnicigol
.relpuoc-otpoehthguorhttnerrucehttimilotnekateb
5elbasiD/elbanE
tupnI
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eht,)nepo(etatsHGIHcigoLaninehW.revirdeht
tibihnitonseodtupnisiht,revewoH.delbaneerastuptuo
ehtybetadpulliwstuptuoeht,erofereht,kcolcpetseht
elihwrevirdehtotdeilppa)ynafi(seslupkcolcforebmun
.delbasidsawti
6tupnIteseR
stuptuoesahp(revirdehtteserlliwtupnisiht,WOLnehW
laitinistitaeblliwrevirdeht,desaelernehW.)elbasidlliw
.)NOBesahP,FFOAesahP(etats
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.WOLevitcasituptuosihT.derrucco
8tuptuOpetS-lluF-nO
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tnuocotdesuebnactuptuosihT.petslluftadenoitisop
sseldrager,devomsahrotomehtspetsllufforebmuneht
situptuosihT.neewtebnispetsorcimforebmunehtfo
.WOLevitca

12 IM483 Operating Instructions Revision R032306
13IM483 Operating Instructions Revision R032306
Connector P2
Table 2.4: Connector P2 - Pin Assignment and Descriptions
WARNING! The IM483 components are sensitive to ElectroStatic
Discharge (ESD). All handling should be done at an ESD protected
workstation.
WARNING! Hazardous voltage levels may be present if using an
open frame power supply to power the IM483.
WARNING! Ensure that the power supply output voltage does not
exceed the maximum input voltage of the IM483.
C384MI noitarugifnoC2Protcenno
#NIP
NOITCNUF
SLIATED
1noitcudeRtnerruC
tsujdA
rotsiserA.tupnItnemtsujdAnoitcudeRtnerruCesahP
yletanoitroporplliw2nipdnanipsihtneewtebdetcennoc
yletamixorppasgnidniwrotomhtobnitnerrucehtecuder
kcolcpetsehtfoegdeevitisoptsalehtretfasdnoces5.
nopudnepedlliwdecudertnerrucfotnuomaehT.tupni
.desurotsiserehtfoeulaveht
2tnerruC
tnemtsujdA
detcennocsirotsiserA.tnemtsujdAtnerruCesahP
mumixamehttsujdaot)DNG(3:2Pdnanipsihtneewteb
rotsiserA.rotomehtnitnerrucesahp TSUM eb
384MIehtrotupnisihtotdetcennoc LLIW .tluafotnihctal
3DNG ylppusrewopehtfo,nruterro,dnuorgehT.dnuorGrewoP
.erehdetcennocsi
4
V+ .CDV84+ot21+.egatloVylppuSrotoM
5BesahP .rotomgnippetsehtfoBØ
6BesahP rotomgnippetsehtfoBØ
7AesahP .rotomgnippetsehtfoAØ
8
AesahP
.rotomgnippetsehtfoAØ

12 IM483 Operating Instructions Revision R032306
13IM483 Operating Instructions Revision R032306
Section 3
Mounting The IM483
This section has recommended mounting instructions for the standard
IM483. Special mounting instructions for any of the connection options
for the IM483 are available in Appendix A: Standard Connection Options,
of this document. An optional heat sink and thermal pad, the H-4X and
TN-48, are available for the IM483. See Appendix C: Cooling Solutions, for
details.
2345678
Thermal Pad
TN-48 or Equivalent
Mounting Plate
or Heatsink Surface
4 X #6 (M3) Threaded
Holes. (See Mechanical,
Figure 2.1 for Hole Pattern
Dimensions)
A
B
C
A
B
C
#6 X 5/8 Stainless
Machine Screw
#6 Split Lock Washer,
Stainless (.04TH, .24 OD)
#6 Flat Washer,
Stainless (.04 TH, .24 OD)
U.S. (4 ea.)
A
B
C
M3 X 0.5 Stainless
Machine Screw
M3 Split Lock Washer,
Stainless (.08TH, .6.20 OD)
M3 Flat Washer,
Stainless (.0.8 TH, 6.20 OD)
Metric (4 ea.)
The torque specification
for the mounting screws
is 5.0 to 7.0 lb-in (0.60 to
0.80 N-m). Do not over-
tighten screws!
Figure 3.1: Mounting Recommendations
NOTE! This diagram focuses on the standard IM483. The
IM483-8P2 and IM483-34P1-8P2 feature connector pins which
may be soldered directly into a user’s PCB design. Mounting
details and a PCB hole pattern may be found in Appendix A:
Standard Connection Options.

14 IM483 Operating Instructions Revision R032306
15IM483 Operating Instructions Revision R032306
Section 4
Theory of Operation
Section Overview
This section will cover the circuit operation for the IM483 microstepping
driver.
n Circuit Operation.
n Microstep Select Inputs.
n Stepping.
n Dual PWM Circuit.
n Fullstep Output.
n Timing.
Circuit Operation
Microstepping drives have a much higher degree of suitability for ap-
plications that require smooth operation and accurate positioning at low
speeds than do half/fullstep drivers and reduction gearing. The IM483,
which can to be set to microstep resolutions as high as 51,200 microsteps/
rev (256 microsteps/step) using a 1.8° stepping motor, is ideal for such
applications.
In order to subdivide motor steps into microsteps while maintaining
positional accuracy, precise current control is required. The IM483 ac-
complishes this by the use of a unique Dual PWM circuit built into the
patented IM2000 Microstep Controller ASIC, which resides at the heart of
the IM483. This PWM circuit uses alternating recirculating/non-recircu-
lating modes to accurately regulate the current in the windings of a two
phase stepping motor.
Figure 4.1: IM483 Block Diagram
INPUT
LOGIC
INPUT
LOGIC
ISOLATION
CIRCUITRY
SINE/COSINE
POSITION
GENERATOR
MICROSTEP
RESOLUTION
SELECTION
STEP CLOCK
DIRECTION
ENABLE
RESET
CURRENT
CONTROL
USER
INTERFACE
POWER
SUPPLY
OPTO
SUPPLY
20kHz CHOP.
OSC
PROTECTION
CIRCUIT
IM2000 MICROSTEP
CONTROLLER
IM483 MICROSTEPPING DRIVER
PHASE A/B
OUTPUT
CIRCUITRY
CURRENT
SENSING
STEPPING
MOTOR
SHORT
CIRCUIT
PROTECTION
OVER CURRENT
PROTECTION

14 IM483 Operating Instructions Revision R032306
15IM483 Operating Instructions Revision R032306
Microstep Select (MSEL) Inputs
Another unique feature of the IM2000 is the ability to change resolutions
at any time. A resolution change can occur whether the motor is being
clocked or is at rest. The change will not take place until the rising edge
of the next step clock input. At this time, the new resolution is latched
and implemented before the step clock pulse takes effect.
If a resolution is chosen such that the sine/cosine output of the IM2000
would not land on an electrical fullstep of the motor, then the IM2000
will automatically align itself to the full step position on the step clock
pulse that would have caused the motor to rotate past the full step. The
step clock pulses, from that point forward, will be equal to the selected
resolution. This feature allows the user to switch resolutions at any time
without having to keep track of sine/cosine location. Because of this, the
On-Full-Step output of the IM483 can easily be used to monitor position.
Conguration settings for the Microstep Resolution are located in Section
7 of this document, Interfacing and Controlling the IM483.
Stepping
The IM2000 contains a built-in sine/cosine generator used for the genera-
tion of Phase A and Phase B position reference. This digitally encoded
9 bit sine and 9 bit cosine signal is directly fed into a digital to analog
converter.
The step clock (SCLK) and direction (DIR) inputs are buffered using
Schmidt triggered buffers for increased noise immunity and are used to
increment or decrement the sine/cosine position generator. The position
generator is updated on the rising edge of the step clock input. It will
increment or decrement by the amount specied by the microstep resolu-
tion select (MSEL) inputs.
The direction (DIR) input determines the direction of the position genera-
tor and hence the direction of the motor. The DIR input is synchronized
to the SCLK input. On the rising edge of the SCLK input the state of the
DIR input is latched in. The position generator will then look to see if
there has been a change in direction and implement that change be-
fore executing the next step. By utilizing this method to implement the
direction change, the noise immunity is greatly increased and no physical
change in the motor occurs if the direction line is toggled prior to the
step clock input.
The enable/disable input does not affect the step clock input. The sine/
cosine generator will continue to update if a signal is applied to the step
clock input.
The IM2000 outputs both sine and cosine data simultaneously when
applying a step clock input. Dual internal look-up tables are used to
output a unique position for every step clock input to enhance system
performance.

16 IM483 Operating Instructions Revision R032306
17IM483 Operating Instructions Revision R032306
Dual PWM Circuit
The IM2000 contains a unique dual PWM circuit that efciently and accu-
rately regulates the current in the windings of a two phase stepping motor.
The internal PWM accomplishes this by using an alternating recirculating/
non-recirculating mode to control the current.
Recirculating
In a recirculating PWM, the current in the windings is contained within
the output bridge while the PWM is in its OFF state. (After the set current
is reached.) This method of controlling the current is efcient when us-
ing low inductance motors,
but lacks response because
of its inability to remove
current from the windings
on the downward cycle of
the sine/cosine wave (See
Figure 4.1).
Non-Recirculating
In a non-recirculating PWM,
the current ows up through
the bridge and back to the
supply in the OFF phase of
the cycle. This method of
controlling current allows for
much better response but re-
duces efciency and increas-
es current ripple, especially in lower
inductance motors (See Figure 4.3).
The IM2000’s PWM utilizes the best
features of both by combining recircu-
lating and non-recirculating current
control. On the rising edge of the
sine/cosine waveform, the PWM will
always be in a recirculating mode.
This mode allows the driver to run
at peak efciency while maintaining
minimum current ripple even with low
inductance motors. On the downward
cycle of the sine/cosine waveform,
the PWM operates in a two part cycle.
In the rst part of its cycle, the PWM
is in a non-recirculating mode to pull
current from the motor windings. In
the second part of the cycle the PWM
Figure 4.3: Non-Recirculating PWM
DRIVE CURRENT
RECIRCULATION
Figure 4.2: Recirculating PWM
DRIVE CURRENT
RECIRCULATION

16 IM483 Operating Instructions Revision R032306
17IM483 Operating Instructions Revision R032306
reverts back to recirculating mode to increase efciency and reduce cur-
rent ripple.
The IM2000 will automatically change the non-recirculating pulse widths
to compensate for changes in supply voltage and accommodate a wide
variety of motor inductances. This method also allows for the use of very
low inductance motors with your IM483 driver, while utilizing a 20kHz
chopping rate which reduces motor heating but maintains high efciency
and low current ripple.
Fullstep Output Signal
The fullstep output signal from the IM483 is an active high output at
connector P1:8. This output will be TRUE for the duration of the full
step. A full step occurs when either Phase A or Phase B crosses through
zero (i.e. full current in one motor winding and zero current in the other
winding). This fullstep position is a common position regardless of the
microstep resolution selected.
The fullstep output can be used to count the number of mechanical
fullsteps that the motor has traveled without the need to count the num-
ber of microsteps in between. A controller that utilizes this output can
greatly reduce its position tracking overhead, thus substantially increasing
its throughput.
Interface guidelines and a sample application for the fullstep output are
located in Section 7 of this document, Interfacing and Controlling the
IM483.
Timing
The direction and microstep resolution select inputs are synchronized
with the positive going edge of the step clock input. When the step clock
input goes HIGH, the direction and microstep resolution select inputs are
latched. Further changes to these inputs are ignored until the next rising
edge of the step clock input.
After these signals are latched, the IM483 looks to see if any changes
have occurred to the direction and microstep resolution select inputs. If
a change has occurred, the IM483 will execute the change before taking
the next step. Only AFTER the change has been executed will the step
be taken. If no change has occurred, the IM483 will simply take the next
step. This feature works as an automatic debounce for the direction and
microstep resolution select inputs.
The reset and enable inputs are asynchronous to any input and can be
changed at any time.

18 IM483 Operating Instructions Revision R032306
19IM483 Operating Instructions Revision R032306
Section 5
Power Supply Requirements
Section Overview
This section covers the power supply requirements of the IM483. Precise
wiring and connection details are to be found in Section 7: Interfacing
and Controlling the IM483. The following is covered by this section:
n Selecting a Power Supply.
n Recommended Wiring.
n AC Line Filtering.
Selecting a Power Supply
Selecting a Motor Supply (+V)
Proper selection of a power supply to be used in a motion system is as
important as selecting the drive itself. When choosing a power supply
for a stepping motor driver, there are several performance issues that
must be addressed. An undersized power supply can lead to poor per-
formance and possibly even damage to your drive.
The Power Supply - Motor Relationship
Motor windings can basically be viewed as inductors. Winding resistance
and inductance result in an L/R time constant that resists the change in
current. To effectively manipulate the rate of charge, the voltage applied
is increased. When traveling at high speeds, there is less time between
steps to reach current. The point where the rate of commutation does not
allow the driver to reach full current is referred to as voltage mode. Ide-
ally you want to be in current mode, which is when the drive is achiev-
ing the desired current between steps. Simply stated, a higher voltage will
decrease the time it takes to charge the coil and, therefore, will allow for
higher torque at higher speeds.
Another characteristic of all motors is back EMF. Back EMF is a source of
current that can push the output of a power supply beyond the maxi-
mum operating voltage of the driver. As a result, damage to the stepper
driver could occur over a period of time.
The Power Supply - Driver Relationship
The IM483 is very current efcient as far as the power supply is con-
cerned. Once the motor has charged one or both windings of the motor,
all the power supply has to do is replace losses in the system. The
charged winding acts as an energy storage in that the current will recircu-
late within the bridge and in and out of each phase reservoir. This results