Intelligent Motion Systems IM481H User Manual

T

TM

intelligent motion systems, inc.

Excellence in Motion

TM

IM481H

ULTRA MINIATURE HIGH PERFORMANCE

MICROSTEPPING DRIVE

OPERATING INSTRUCTIONS

370 N. MAIN ST., PO BOX 457, MARLBOROUGH, CT 06447

PH. [phone], FAX [phone]

Internet: http://www.imshome.com, E-Mail: [e-mail]

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.

TM

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
indemnifies Intelligent Motion Systems, Inc., against all damages.

IM481H Ultra Miniature High Performance Microstepping Drive

Revision 05.12.05

© Intelligent Motion Systems, Inc.

All Rights Reserved

SECTION PAGE

1 LIST OF T ABLES AND FIGURES ..................................... 1

2 INTRODUCTION ............................................................... 2

3 PIN ASSIGNMENT AND DESCRIPTION ........................... 3

4 ELECTRICAL SPECIFICA TIONS ...................................... 4

5 THERMAL SPECIFICA TIONS ........................................... 4

6 MECHANICAL SPECIFICA TIONS

6.1 DIMENSIONAL IMFORMA TION ........................................ 5

6.2 MOUNTING INFORMATION .............................................. 6

7 OUTPUT CURRENT

7.1 DETERMINING OUTPUT CURRENT ................................. 7

7.2 SETTING OUTPUT CURRENT .......................................... 8

7.3 RESISTOR T ABLE ........................................................... 9

8 MOTOR

8.1 MOTOR SELECTION.......................................................10

8.2 CONNECTING THE MOTOR............................................10

9 POWER REQUIREMENTS

9.1 MOTOR POWER.............................................................12

9.2 +5 VDC INPUT ................................................................13

10LAYOUT AND INTERF ACE GUIDELINES .................................14

1 1 MICROSTEP SELECTION ...............................................14

12FULLSTEP OUTPUT SIGNAL...................................................16

13TIMING .....................................................................................16

14INPUTS ....................................................................................17

15AUTOMATIC CURRENT REDUCTION .......................................18

16FAUL T PROTECTION ...............................................................19

18THERMAL REQUIREMENTS....................................................19

19OPTIONS/ACCESSORIES .......................................................20

Appendix A - Recommended Cable Configurations........................21

WARRANTY.................................................................................30

LIST OF FIGURES

Figure 1 DIMENSIONAL INFORMA TION .............................. 4

Figure 2 MOUNTING INFORMA TION .................................... 6

Figure 3 SETTING OUTPUT CURRENT................................ 9

Figure 4 MOTOR CONNECTIONS.......................................12

Figure 5 POWER CONNECTIONS ......................................14

Figure 6 MICROSTEP RESOLUTION SELECTION..............16

Figure 7 INPUTS .................................................................18

Figure 8 FA UL T IN/RESET - INTERFACE CIRCUIT..............18

Figure 9 RESET TIMING .....................................................18

Figure 10 MULTIPLE DRIVES - ONE RESET........................18

Figure 1 1 AUT OMA TIC CURRENT REDUCTION ...................19

LIST OF TABLES

T able 1 ELECTRICAL SPECIFICA TIONS ............................ 4

T able 2 THERMAL SPECIFICA TIONS................................. 4

T able 3 RESISTOR T ABLE ................................................10

T able 4 POWER SUPPL Y SPECIFICA TIONS ....................13

T able 5 MICROSTEP SELECTION.....................................15

1

SECTION 2

The IM481H is a high performance, yet low cost microstepping driver that utilizes
advanced hybrid technology to greatly reduce size without sacrificing features. The
IM481H is exceptionally small, easy to interface and use, yet powerful enough to handle
the most demanding applications.

The IM481H has 14 built in microstep 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 designs, allowing the use of low
inductance motors improving high speed performance and system efficiency.

The IM481H, because of its ultra 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 microstepping, reducing cost and eliminating
potential maintenance.

OPTIONAL INTERFACE BOARD The INT-481 is a plug on interface board which can be
used with the IM481H to facilitate testing or in situations where panel mounting is
preferred

The INT-481 contains extra circuitry which includes: Opto isolators for step clock,
direction, enable, and reset, along with extra fault detection circuits, +5vdc supply, input
capacitor, and fault and power LED’s. Wiring is done through a 15 pin screw terminal
header. A four position dip switch is supplied for microstep resolution selection.

INTRODUCTION

FEATURES

•Very Low Cost

•Ultra Miniature 1.1” x 2.7” x 0.17”

•High Input Voltage (+12 to +48Vdc)

•High Output Current (1.5 Amps RMS, 2.3 Amps Peak)

•Advanced Hybrid Design

•Replaces Mechanical Gearing for Smoothness and Positioning

•Designed for High Performance, Low Inductance Stepping Motors

•20 KHz Chopping Rate

•Up to 10 MHz Step Clock Rate

•14 Selectable Microstepping Resolutions that can be changed On-The-Fly.

•Up to 51,200 Steps/Rev with a 1.8

o

Motor

•Automatically Switches between Slow and Fast Decay for Unmatched

Performance

•At Full Step Output

2

SECTION 3

PIN # PIN NAME PIN FUNCTION

PHASE A Phase A of the stepping motor is connected between pin 1 and pin 2. See section 8.

1,2

PIN ASSIGNMENT AND DESCRIPTION

CURRENT

3

REDUCTION
ADJUST

CURRENT

4

REFERENCE

CURRENT

5

ADJUSTMENT

FAULT INPUT A low signal on this input will generate a latched fault condition. See section 16.

6

RESOLUTION

7-

SELECT 0-3

10

SUPPLY

11

GROUND

+V Supply voltage input. See section 9.

12

RESET INPUT When low, this input will reset the driver ( phase outputs will disable ). When released,

13

+5V +5Vdc supply input. This supply is used to power the internal logic. The +5Vdc supply

14

STEP CLOCK

15

INPUT

Phase current reduction adjustment input. A resistor connected between this pin and pin
4 ( if used to set motor phase current ) will proportionately reduce current in both
windings approximately .5 seconds after the last positive edge of the step clock input.
See section 15.

Phase current reference output. A resistor is connected between this 1 mA current
source output and the Ground pin ( pin 11 ) to generate the voltage used to set the peak
phase current in the motor. See section 7.

Phase current adjustment input. A voltage applied to this input sets the peak phase
current in the motor. See section 7.2.

Microstep resolution select inputs. Used to select the number of microsteps per step of
the motor. See section 11.

Supply voltage ground ( return ). See section 9.

the driver will be at its initial state ( phase A off, phase B on ). See section 14.

should be referenced to pin 11( supply ground ). See section 9.2.

A positive going edge on this input advances the motor one increment. The size of the
increment is dependent on the microstep select inputs See section 13.

DIRECTION

16

INPUT

ENABLE

17

INPUT

ON-FULL-

18

STEP OUTPUT

FAULT

19

OUTPUT

PHASE B Phase B of the stepping motor is connected between pin 20 and pin 21. See section 8.

20-

This input is used to change the direction of the motor. Physical direction also depends
on the connection of the motor windings. See section 13.

This input is used to enable/disable the output section of the driver. When high, the
outputs are enabled. However, this input does not inhibit the step clock. Therefore when
enabled the outputs will update by the number of clock pulses ( if any ) applied to the
driver while it had been disabled. See section 14.

This totem-pole output indicates when the driver is positioned at a full step. This output
can be used to count the number of full steps the motor has moved, regardless of the
number of microsteps in between. This output is active high. See section 12.

This totem-pole output indicates a short circuit has occurred or a low signal was
detected on the Fault input. This output is active high. See section 16

21

3

SECTION 4

ELECTRICAL SPECIFICATIONS

Table 1

Test Parameters: T
TEST CONDITION

INPUT VOLTAGE ....................................................................................... 12 ....... 45 ........ 48

PHASE OUTPUT CURRENT ......................................

PHASE OUTPUT CURRENT .....................................

QUIESCENT CURRENT (+v, pin 12) ..........

QUIESCENT CURRENT (+5vdc, pin 14) ....

ACTIVE POWER DISSIPATION ..........................

LOW LEVEL INPUT VOLTAGE .............................

HIGH LEVEL INPUT VOLTAGE ...................

HIGH LEVEL INPUT VOLTAGE ................................

INPUT PULL-UP RESISTANCE .................

INPUT PULL-UP RESISTANCE .....................

INPUT PULL-UP RESISTANCE ................................

LOW LEVEL OUTPUT CURRENT .....................

HIGH LEVEL OUTPUT CURRENT ....................

LOW LEVEL OUTPUT VOLTAGE ..........................

HIGH LEVEL OUTPUT VOLTAGE ..........................

= 25oC,+V = 48v

A

MIN TYP MAX UNITS

* .......... V

RMS .......................0.14 ...................1.5 .......... A

PEAK ..................................................2.3 .......... A

INPUTS/OUTPUTS FLOATING .....................25 ...................... mA

INPUTS/OUTPUTS FLOATING ................................... 40 ........ mA

I

= 1A RMS ............................................2.0 ......... W

OUT

ALL INPUTS ..................... .......................0.8 .......... V

ALL INPUTS EXCEPT RESET ......................2.0 ........................ V

RESET ...................................2.3 ......................... V

FAULT IN, RES SEL 0-3, ENABLE ....... 4.4 ......4.7 ........5.0 ........ kΩ

STEP CLOCK, DIRECTION ...........2.1 ......2.2 ........2.3 ........kΩ

RESET .......................0.9 ......1.0 ........1.1 ........kΩ

FAULT, FULLSTEP ................ 24 ..................................mA

FAULT, FULLSTEP .................-2 .................................. mA

I

=24 mA ...............................................0.4 .......... V

OL

IOH = -2 mA ....................4.5 .................................... V

* INCLUDES BACK EMF OF MOTOR

SECTION 5

THERMAL SPECIFICATIONS

STORAGE TEMPERATURE ................................................ -40 TO +125

OPERATING TEMPERATURE ................................................0 TO +50

‡REAR MOUNTING SURFACE (MAX) ....................................... +70

‡ADDITIONAL COOLING MAY BE REQUIRED TO LIMIT REAR MOUNTING SURFACE

Care should be taken when choosing a heatsink to ensure that there is good thermal flow,
otherwise hot spots may occur in the IM481H which will reduce the effectivness of the
thermal protection.

Table 2

O

C

O

C

O

C

NOTE:

WARNING ! Rear mounting surface of driver contains

different voltages and must be keep isolated when attached
to a conductive surface !

An optional thermal pad ( Part # TI-481 ) and heat sink ( Part # H-481 ) is available
for the IM481H

4

SECTION 6.1

MECHANICAL SPECIFICATIONS

DIMENSIONAL INFORMATION

Dimensions in Inches (mm)

IM481H

*Wt: 0.512 oz.

14.6 gms.

INT-481

*Wt: 1.02 oz.

29.0 gms.

H-481

*Wt: 2.40 oz.

68.1 gms.

1.550

(39.37)

0.275

(6.99)

1.100

(27.9)

0.178
(4.5)

0.225
(5.7)

0.563

(14.3)

21

12345

PIN 1

OPTO/+5 V

3

1

JP1

678

0.498
(12.6)

(62.23)

ENOFF/ENON
1

JP2

9

3.000
(76.2)

2. 450

3

10

11

2 XØ 0.143

(3.6 ) Thru

1.875

(47.6)

2.700
(68.6)

2.450
(62.2)

2.225
(56.4)

2 X Ø 0.150

(3.8)THRU

0.100
(25.4)

121314

2.872

(72.9)

1516171819

1

SW1

1
2
3
4

0.016
(0.4) SQ.

MS0
MS1
MS2
MS3

GRN

RED

FAULT POWER

LED1

0.175

0.575

(14.6)

(4.4)

65°
TYP.

0.312
(7.9)

(23.37)

0.620

(15.75)

0.920

0.175

Heat Sink
This Side

0.058
(1.5)

21 Pin Right Angle
Connector
HY481-CN021

Heat Sink
This Side

1.312
(33.3)

1.100
(27.9)

0.211
(5.4)

* Does not include mounting hardware.

2.450
(62.2)

2 X Ø 0.177
(4.5) Thru

0.550
(13.9)

2 X #6-32
Tapped Thru

5

SECTION 6.2

MOUNTING INFORMATION

IM481-H Driver and H-481 Heat Sink Direct Mount on PCB

D

F

*

4

1

A

C

B

PCB

Hole Pattern for Direct PCB Mounting

Dimensions are in Inches (mm)

Ø 0.250 +0.003 / - 0.0

1.875

(6.35 +0.08 / - 0.0)

0.064 Pad, 0.031 Hole
(1.6 Pad, 0.78 Hole)

0.240
(6.1)

Pin #1

0.063
(1.6)

0.100 Typ
(2.54 Typ)

(47.63)

NOTE: Components are
described in the table on the
following page.

3

G

0.096
(2.43)

H-481 Heat Sink

NOTE: The hardware items “A” through “H” are supplied with the
H-481 Heat Sink Kit. If the H-481 is not used, the mounting hardware is not supplied.

NOTE: The torque specification for the #6-32 INT-481 and IM481H mounting screw is

5.0 - 7.0 in-lbs. (See the hardware list on the following page.)

* The Isolating Thermal Pad (TI-481) item “4” is supplied with the INT-481 Interface

Board. If the INT-481 is not used, the Thermal Pad must be ordered seperately.

WARNING! The Heat Sink mounting surface must be a smooth, flat surface
with no burrs, protrusions, cuttings or other foreign objects.

WARNING! If you are planning to wash your PCB it must be done prior to
adding the IM481H Driver or damage will occur.

6

IM481-H Driver, INT-481 Interface Board, H-481 Heat Sink Panel Mount

3

E

F

*

4

1

2

H

0.915

(23.25) Ref.

C
B

A

IM481-H Driver, INT-481 Interface Board Panel Mount without Heat Sink

*

4

1

A

C

B

2

0.180

(4.57) Ref.

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AwercSdaeHnaP"

BrehsaWkcoLtilpS6#2

CkcihT"030.0,DI"541.0,DO"052.0,rehsaWtalF6#2

DwercSdaeHnaP"8/31x23-8#2

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HgnoL"005.0,DI"171.0,DO"213.0,recapS2

8/5x23-6#2

* The Isolating Thermal Pad (TI-481) item “4” is supplied with the INT-481 Interface

Board. If the INT-481 is not used, the Thermal Pad must be ordered seperately.

7

OUTPUT CURRENT

SECTION 7.1

DETERMINING THE OUTPUT CURRENT

For any given motor, the OUTPUT CURRENT used for MICROSTEPPING is determined
differently from that of a HALF/FULL STEP driver.

In the IM481H, a sine/cosine output function is used in rotating the motor. Therefore, when
microstepping, the specified phase current of the motor is considered an RMS value.

The CURRENT ADJUSTMENT RESISTOR used to set the output current of the IM481H
sets the peak output of the sine/cosine waves not the RMS value. Therefore the specified
motor current (which is the RMS value) should be multiplied by 1.4 to determine the PEAK
value to which the IM481H will be set.

EXAMPLE:

If a motor has a specified PHASE CURRENT of 0.75 amps per phase, then:

0.75 amps X 1.4 = 1.05 amps peak

The Resistor Value = OUTPUT CURRENT X 1000 or in this example:

1.05 X 1000 = 1050 Ω.

Table 3 shows commercially available 1% resistors for a given current.

NOTE: Stepper motors can be configured as 4, 6, or 8 leads. Each configuration requires
different currents. Shown below are the different lead configurations and the procedures to
determine their output current.

4 Lead Motors: Multiply the specified phase current by 1.4 to determine the peak

6 Lead Motors: 1) When configuring a 6 lead motor in a half coil configuration ( i.e.

2) When configuring the motor so the full coil is used (i.e. connected

8 Lead Motors: SERIES CONNECTION: When configuring the motor windings in

PARALLEL CONNECTION: When configuring the motor windings in

NOTE:

After determining the peak output current, use table 4 to choose the proper
current reference resistor value.

output current.

connected from one end of the coil to the center tap (high speed
configuration)) multiply the specified per phase (or unipolar) current
rating by 1.4 to determine the peak output current.

from end to end with the center tap floating (higher torque
configuration)) use the per phase (or unipolar) current rating as the
peak output current.

series, use the per phase (or unipolar) current rating as the peak
output current, or multiply the bipolar current rating by 1.4 to
determine the peak output current.

parallel, multiply the per phase (or unipolar) current rating by 1.96 or
the bipolar current rating by 1.4 to determine the peak output current.

8

SECTION 7.2

SETTING OUTPUT CURRENT

The OUTPUT CURRENT on the IM481H is set by applying a voltage to pin 5 (current
adjustment). The output current is set as follows:

PEAK OUTPUT CURRENT (Amps) = Volts applied to pin 5

EXAMPLE:

1.4 volts applied to pin 5 will set the peak output current of the IM481H to 1.4
amps per phase.

To generate the reference voltage needed to set the peak output current of the driver, a
1mA current source is provided (pin 4, Current Reference ). By connecting a resistor (

1/8

watt or higher ) between pin 4 and pin 11 ( Ground ) a reference voltage is generated. Pin
4 is then connected to pin 5 ( Current Adjustment) to set the peak per phase output
current of the driver ( See Figure 3 ).

The relationship between the output current and the resistor value is as follows:

PEAK OUTPUT CURRENT (Amps) x 1000 = Resistor Value (Ohms)

EXAMPLE:

To set the peak output current of the IM481H to 1.4 Amps:

1.4 ÷ .001 = Resistor Value = 1400 .

Table 3 shows the standard 1% resistor values with respect to the peak output current.

NOTE: When using the Current Reference output to set the output current of the

IM481H, care should taken to keep the connections as short as possible
to help minimize the noise coupled into the driver.

Current Reference

Current Adjustment

1234567

Current

Adjustment

Resistor

Supply Ground

8910111213

14151617

18192021

Figure 3

WARNING! A Current Adjustment Resistor is always necessary to keep the

Driver and/or Motor in safe operating range.

DO NOT operate the IM481H Driver without a Current Adjustment
Resistor!

9

SECTION 7.3

RESISTOR TABLE

Table 3

PEAK OUTPUT CURRENT REFERENCE RESISTOR VALUE (1%)
(AMPS) (VOLTS) (OHMS)

0.20 ................................ 0.20 ............................. 200

0.25 ................................ 0.25 ............................. 249

0.30 ................................ 0.30 ............................. 301

0.35 ................................ 0.35 ............................. 348

0.40 ................................ 0.40 ............................. 402

0.45 ................................ 0.45 ............................. 453

0.50 ................................ 0.50 ............................. 499

0.55 ................................ 0.55 ............................. 549

0.60 ................................ 0.60 ............................. 604

0.65 ................................ 0.65 ............................. 649

0.70 ................................ 0.70 ............................. 698

0.75 ................................ 0.75 ............................. 750

0.80 ................................ 0.80 ............................. 806

0.85 ................................ 0.85 ............................. 845

0.90 ................................ 0.90 ............................. 909

0.95 ................................ 0.95 ............................. 953

1.00 ................................ 1.00 ........................... 1000

1.05 ................................ 1.05 ........................... 1050

1.10 ................................ 1.10 ........................... 1100

1.15 ................................ 1.15 ........................... 1150

1.20 ................................ 1.20 ........................... 1210

1.25 ................................ 1.25 ........................... 1240

1.30 ................................ 1.30 ........................... 1300

1.35 ................................ 1.35 ........................... 1330

1.40 ................................ 1.40 ........................... 1400

1.45 ................................ 1.45 ........................... 1430

1.50 ................................ 1.50 ........................... 1500

1.55 ................................ 1.55 ........................... 1540

1.60 ................................ 1.60 ........................... 1580

1.65 ................................ 1.65 ........................... 1650

1.70 ................................ 1.70 ........................... 1690

1.75 ................................ 1.75 ........................... 1740

1.80 ................................ 1.80 ........................... 1780

1.85 ................................ 1.85 ........................... 1820

1.90 ................................ 1.90 ........................... 1870

1.95 ................................ 1.95 ........................... 1960

2.00 ................................ 2.00 ........................... 2000

2.05 ................................ 2.05 ........................... 2050

2.10 ................................ 2.10 ........................... 2100

WARNING! Although stepping motors will run hot when
configured correctly, damage may occur to a motor if a higher than
specified current is used. Most specified motor currents are maximum
values. Care should be taken when exceeding these ratings.

10

MOTOR

SECTION 8.1

MOTOR SELECTION

The IM481H is a Bipolar driver which works equally well with both Bipolar and Unipolar
motors, ( i.e. 8 and 4 lead motors and 6 lead center tapped motors (see section 8.2,
Connecting the Motor)).

To maintain a given set motor current, the IM481H chops the voltage using a constant
chopping frequency and a varying duty cycle. Duty cycles that exceed 50% can cause
unstable chopping. This characteristic is directly related to the motor’s winding
inductance. To avoid this situation, it is necessary to choose a motor with a low winding
inductance. The lower the winding inductance, the higher the step rate possible.

The maximum per phase motor inductance for the IM481H is calculated as follows:

Max. per Phase Inductance (mH) = 2 x Supply Voltage ÷ 10
NOTE: In calculating the maximum phase inductance, when using an unregulated

Since the IM481H is a constant current source, it is not necessary to use a motor that is
rated at the same voltage as the supply voltage. What is important is that the IM481H is
set to the motor’s rated current.

The higher the voltage used the faster the current can flow through the motor coils. This in
turn means a higher step rate. Care should be taken not to exceed the maximum voltage
of the driver.

Therefore in choosing a motor for a system design, the best performance for a specified
torque is a motor with the lowest possible winding inductance used in conjunction with the
highest possible driver voltage.

power supply, the minimum supply output voltage should be used.

SECTION 8.2

CONNECTING THE MOTOR

Phase A of the Stepping Motor is connected between pins 1 and 2. Phase B of the
Stepping Motor is connected between pins 20 and 21. The following drawings in figure 4
illustrates the connection of 4,6, and 8 Lead Stepping Motors to the IM481H Driver.

NOTE: To reduce the transmission of EMI from the motor cables, a twisted pair

NOTE: The physical direction of the motor with respect to the direction input will

sheilded cable is recommended if the driver to motor cabling is in excess of
one foot. Motor leads should not exceed 100 feet. Refer to Section 10,
Recommended Wiring, for further information.

depend on the connection of the motor windings. To reverse the direction of
the motor with respect to the direction input, switch the wires on either
phase A or phase B outputs.

WARNING! Do not connect or disconnect the AC power leads
or the motor leads with power applied!

11

MOTOR CONNECTIONS

1

2

20

21

8 LEAD MOTOR

SERIES CONNECTION

1

2

NC

NC

20

21

PHASE A

PHASE B

PHASE A

PHASE B

1

2

PHASE A

PHASE B

20

21

8 LEAD MOTOR

PARALLEL CONNECTION

1

NC

2

PHASE A

PHASE B

20

21

NC

HIGHER SPEED CONFIGURATION

6 LEAD MOTOR

( HALF COIL )

NC: NO CONNECTION

Figure 4

12

HIGHER TORQUE CONFIGURATION

6 LEAD MOTOR

( FULL COIL )

NC: NO CONNECTION

1

2

PHASE A

PHASE B

20

21

4 LEAD MOTOR

POWER REQUIREMENTS

SECTION 9.1

Pins 11 (ground), and 12 (+V) are used to connect the motor DC power to the IM481H.
Two local capacitors are needed, connected between pins 11 and 12 and located as
close to the pins as possible, to insure stable operation.

The first capacitor is a low impedance, aluminum electrolytic. The continuous operating
voltage of the capacitor should exceed the maximum supply voltage as well as any
additional voltage caused by the motors back EMF. The value of the capacitor should be
approximately 150 microfarads for every 1 amp of peak per phase output current.

EXAMPLE: For a peak output current of 1.4 amps, and a supply voltage of 45 volts, a
220uf 50v capacitor is recommended.

Along with the aluminum electrolytic, a 0.1 microfarad ceramic capacitor must be used to
filter out high frequency noise. It should be located between the IM481H’s power input
pins and the aluminum electrolytic capacitor. The continuous operating voltage of the
capacitor should exceed the maximum supply voltage as well as any additional voltage
caused by the motors back EMF.

MOTOR POWER

POWER SUPPLY SPECIFICATIONS

Table 4

Recommended Type: ..............Unregulated DC.

Ripple Voltage ............................. ±10% max.

Output Voltage ......................... +12 to +45Vdc

NOTE: RECOMMENDED POWER SUPPLY IMS: PART # ISP200-4

NOTE:

With the exception of IMS Power Supplies, Switching Power Supplies and
regulated linears with overcurrent protection are not recommended because of
their inability to handle surge currents. If multiple drivers are to be run off of one
power supply each drive should have separate power and ground wires that
connect directly to the output capacitor of the power supply.

*Output Current .................. 0.75 Amps (TYPICAL)

*THE OUTPUT CURRENT NEEDED IS DEPENDENT ON THE SUPPLY VOLTAGE,

MOTOR SELECTION, AND LOAD.

W A R N I N G : When using an unregulated power supply, care
should be taken that the output voltage does not exceed the
maximum driver input voltage because of variations in line
voltage. It is recommended that a input line filter be used on the
power supply to limit voltage spikes to the driver!!

W A R N I N G : Do not connect or disconnect motor leads with
power applied !! Do not connect or disconnect power supply
with power applied !!

13

SECTION 9.2

+5 VDC INPUT

The IM481H requires an external regulated +5Vdc power supply. The supply is connected
between pins 11 (ground), and 14 (+5vdc). A 22 microfarad 10v tantilum capacitor must
be placed as close to the IM481H as possible between the +5vdc input pin (14) and
ground.

The +5vdc supply ground and the motor supply ground should not be connected together
at the power supplies. The common ground connection between the motor power supply
and the +5vdc supply should be made at the ground pin of the additional electrolytic
capacitor used for the motor supply (see section 9.1)

Figure 5 shows the proper connection of the external +5vdc supply to the IM481H.

NOTE:

Care should be taken when using this supply not to couple noise from
external circuits into the IM481H which could cause erratic operation or
damage.

Figure 5

14

+5VDC

SUPPLY

MOTOR

SUPPLY

SECTION 10

LAYOUT AND INTERFACE GUIDELINES

Logic level signals should not run parallel to motor phase signals. The motor phase signals
will introduce noise into the logic level signals and can make the system unreliable. Motor
phase signals should run as pairs and should be separated from other signals by ground
traces where possible.

When leaving the board, motor cables should not be run parallel with other wires and
phases should be wired using twisted pairs. If motor cabling in excess of 1 foot is required,
the use of a shielded twisted pair cable is recommended to reduce the transmission of
EMI. The shield must be tied to AC ground at the driver end only. The motor end must be
left floating.

If more then one driver is to be connected to the same power supply, separate power and
ground connections from each driver to the power supply should be used.

The power supply cables need to be a twisted pair if power is connected from a source
external to the board. If multiple drivers are used with an external power source, and it is
not possible to run separate power and ground connections to each driver, a low
impedance electrolytic capacitor equivalent to 2 times the total capacitance of all the driver
capacitors ( see section 9 Power requirements ) and of equal voltage must be placed at
the power input to the board.

MOTOR CABLES

Dual Twisted Pair Shielded (Separate Shields)
<

5 feet ............................................................ Belden Part # 9402 or equivalent 20 Gauge

> 5 feet ............................................................ Belden Part # 9368 or equivalent 18 Gauge

POWER SUPPLY CABLES

Twisted Pair (Jacketed)

4 Amps DC current ....................................... Belden Part# 9740 or equivalent 18 Gauge

<

> 4 Amps DC current ....................................... Belden Part# 8471 or equivalent 16 Gauge

SECTION 11

MICROSTEP SELECTION

The number of microsteps per step is selected by pins 7 thru 10. Table 5 shows the
standard resolution values along with the associated input settings ( See section 14 ­Inputs ).

The microstep resolution can be changed at any time. There is no need to reset or cycle
power. On-the-fly “gear shifting” facilitates high speed slewing combined with high
resolution positioning at either end of the move.

When the number of microsteps per step are changed such that the IM481H does not fall
on a full step (i.e. zero crossing of the sine/cosine waveforms) the IM481H will re-adjust
itself at the next pulse that would overshoot the full step position. This feature allows the
IM481H to re-adjust the motor to position no matter what resolution is chosen or when it is
changed.

15

MICROSTEP SELECTION

RESOLUTION STEPS/REV RESOLUTION RESOLUTION RESOLUT ION RESOLUTION
(Microsteps/Step) (1.8
PIN 7 PIN 8 PIN 9 PIN 10

o

Step Motors) SELECT 0 SELECT 1 SELECT 2 SELECT 3

BINARY

2 400 LOW LOW LOW LOW

4 800 HIGH LOW LOW LOW

8 1,600 LOW HIGH LOW LOW

16 3,200 HIGH HIGH LOW LOW

32 6,400 LOW LOW HIGH LOW

64 12,800 HIGH LOW HIGH LOW

128 25,600 LOW HIGH HIGH LOW

256 51,200 HIGH HIGH HIGH LOW

DECIMAL

5 1,000 LOW LOW LOW HIGH

10 2,000 HIGH LOW LOW HIGH

25 5,000 LOW HIGH LOW HIGH

50 10,000 HIGH HIGH LOW HIGH

125 25,000 LOW LOW HIGH HIGH

250 50,000 HIGH LOW HIGH HIGH

Table 5

ILLEGAL SETTINGS: MAY CAUSE ERRATIC OPERATION

LOW HIGH HIGH HIGH

HIGH HIGH HIGH HIGH

Figure 6

16

SECTION 12

FULLSTEP OUTPUT SIGNAL

The FULLSTEP output signal from the IM481H is an active high output at pin 18. This
output is TRUE for the duration of the full step. A full step occurs when either Phase A or
Phase B cross through zero (i.e. full current in one winding and zero current in the other
winding). This fullstep position is a common position no matter what resolution is
selected.

The fullstep output can be used to count the number of mechanical full steps the motor
has traveled without having to count the number of microsteps in between. A controller
that utilizes this output can greatly reduce its position tracking overhead and thus
substantially increasing its throughput.

SECTION 13

TIMING

The Direction and Microstep Resolution Select inputs are syncronized with the positive
going edge of the Step Clock input. When the Step Clock input goes high, the Direction
and Microstep Select inputs are latched and further changes to these inputs are ignored
until the next rising edge of the Step Clock input.

After these signals are latched, the IM481H looks to see if any changes have occured to
the Direction and the Microstep Select inputs. If a change has occurred, the IM481H 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 occured the IM481H will simply take
the next step. (This feature works as an automatic debounce for the Direction and
Microstep Select inputs.)

The minimum pulse width for the Step Clock input is 75nS. The typical execution time for
a Direction or Microstep Select change is 100nS. The typical execution time for a Step
input is 100nS.

The Reset and Enable inputs are asynchronous to any input and can be changed at any
time.

The Reset requires a minimum pulse width of 10µS (See Section 14 for more
information).

The Fullstep output typically occurs 75nS after the positive edge of the Step Clock
(excluding changes to the Direction or the Microstep Select inputs).

17

SECTION 14

INPUTS

The inputs to the IM481H are internally pulled up
to the +5VDC internal supply. Figure 7 shows the
inputs and their associated pull up resistor
values. See Section 4, Electrical Specifications,
for resistor tolerence.

An open collector output is recommended
when interfacing with the IM481H.

On power up, or if the Reset Input is Closed,
the internal reset circuit will hold the input
low for 100 to 300 milliseconds. The
“holding” time does not begin until the Reset

Input is Opened. (See Figure 9.)

W A R N I N G! When interfacing the FAULT IN or RESET input, an
open collector, tri-state output, or a blocking diode is REQUIRED or

damage may occur to internal circuits. (See Figure 8.)

Fault In
Resolution Select 0
Resolution Select 1
Resolution Select 2
Resolution Select 3

Reset

+5 VDC

Step Clock

Direction

Enable

1
2
3
4
5
6
7
8

9
10
11
12
13
14
15
16
17
18
19
20
21

Figure 7

4.7k Ω

4.7k Ω

4.7k Ω

4.7k Ω

4.7k Ω

1k Ω

2.2k Ω

2.2k Ω

4.7k Ω

+5V

FAULT IN/RESET

RESET BUTTON

Circuit

Circuit

Open

Closes

INPUT

Circuit

Open

at T=0

OR

Internal Reset Hold Time

Starts When Circuit Opens

0 100 200 300

When controlling multiple drives with a single
Reset you must install blocking diodes at the
input (Pin 13) of each drive. Because of the
slight differences in Reset timing, this will
prevent the drives from latching the Reset
Input in the LOW state. (See Figure 10.)

INTERFACE

Figure 8

Milliseconds

Figure 9

18

1N914 OR EQUIVALENT

CIRCUIT

RESET

BUTTON

FAULT IN /RESET

INPUT

+5 V

1N914 OR

EQUIVALENT

1N914 OR

EQUIVALENT

1N914 OR

EQUIVALENT

Figure 10

UNIT #1

13

13

13

RESET
INPUT

UNIT #2

RESET
INPUT

UNIT #3

RESET
INPUT

SECTION 15

AUTOMATIC CURRENT REDUCTION

Built into the IM481H is the ability to automatically reduce the current in the motor
windings after the completion of a move. The reduction occurs approximately .5 seconds
after the last positive going edge of the Step Clock input. The IM481H will then revert
back to the original current setting at the next positive going edge of the Step Clock input.

To utilize this feature, the current reference output must be used to adjust the output
current of the IM481H and a resistor must be connected between pins 3 & 4 (see Figure

6). The value of the resistor will determine the amount of current reduction.

The amount of current per phase in the current reduction mode is related to the value of
the current reference resistor and the current reduction resistor. When the current
reduction circuit is activated, the current reduction resistor is paralleled with the current
adjustment resistor. The parallel combination of the current reference and current
reduction resistors determine the reduced current level. The relationship between the
output current and the resistor's values is as follows:

.001 x *R(Current Adjust) x R(Current Reduction)

Output Current Reduced (Amps)=

R(Current Adjust) + R(Current Reduction)

Output Current Reduced x R(Current Adjust)
R(Current Reduction) =
.001 x R(Current Adjust) - Output Current Reduced

NOTE: Resistor values are in ohms.

OR

NOTE:

CURRENT

REDUCTION

RESISTOR

CURRENT

ADJUSTMENT

RESISTOR

Figure 11

When connecting the current reduction resistor between pins 4 and 5, the
connections should be made as short as possible to help minimize noise
coupled into the driver.

19

SECTION 16

FAULT PROTECTION

The IM481H is internally protected against over temperature, and over current.

The over temperature set point is between 60 and 70 °C. Care should be taken when
choosing and installing a heat sink so that there is a good thermal conduction, otherwise
hot spots may occur in the IM481H which will reduce the operating thermal range.

The over current protection consists of PHASE to PHASE, and +V to PHASE.

If an output driver in the IM481H detects an over temperature condition it will shut down
but will not activate the fault output. Once the temperature drops to a safe operating
temperature, the IM481H will resume operation.

If an over current fault is detected by the IM481H, the outputs will be disabled and cannot
be re-enabled without resetting the driver or by cycling power. At the same time the active
high FAULT output (pin 19) is enabled.

The FAULT IN input (pin 6) can be used to force a fault condition. When pulled low the
signal is latched and the outputs will be disabled. The fault condition can only be cleared
by cycling power or resetting the driver.

SECTION 17

THERMAL REQUIREMENTS

The IM481H may require heat sinking to maintain a safe operating temperature. Care
should be taken when mounting the IM481H to a heat sink with an electrically conductive
surface that an isolating thermal pad is used.

WARNING ! Rear mounting surface of driver contains
different voltages and must be kept isolated when attached
to a conductive surface !

NOTE:

An optional thermal pad ( Part # TI-481 ) and heat sink ( Part # H-481 ) is available
for the IM481H

The watts dissipated by the IM481H can be calculated as follows:

Watts Dissipated = ( 0.6 x ( Peak per Phase Output Current )

EXAMPLE: Peak per Phase Output Current = 1.4 amps

Watts Dissipated = 1.18

2

)

20

SECTION 18

OPTIONS/ACCESSORIES

DESCRIPTION PART NUMBER

Thermal Pad TI - 481

Interface Board INT-481

Heat Sink ( Includes mounting hardware ) H-481

21 Pin Right Angle Connector HY481-CN021

Small End Screw Driver SD1

21

APPENDIX A

Recommended Cable Configurations:

DC Supply to IMS Driver

Cable length, wire gauge and power conditioning devices play a major role
in the performance of your IMS Driver and Motor.
NOTE: The length of the DC power supply cable to the IMS Driver should
not exceed 50 feet.
Example A demonstrates the recommended cable configuration for DC
power supply cabling under 50 feet long. If cabling of 50 feet or longer is
required, the additional length may be gained by adding an AC power
supply cable (see Examples B & C).
Correct AWG wire size is determined by the current requirement plus cable
length. Please see the IMS Driver Supply Cable AWG Table in this
Appendix.

Example A – Cabling Under 50 Feet, DC Power

To IMS Driver

π

Type RFI Filter

≥ Required Current

-

+

Ferrite
Beads

Cable Length

less than 50 Feet

DC Voltage from

Power Supply

+

500 µf

Per Amp

Shielded Twisted Pair

IMS Driver Supply Cable AWG Table)

Shield to Earth Ground

-

22

(Wire Size from

on Supply End Only

f

Example B – Cabling 50 Feet or Greater,
AC Power to Full Wave Bridge

To Cable A

Full Wave Bridge

Shielded Twisted Pair

(Wire Size from

IMS Driver Supply Cable AWG Table)

+

NOTE:
Connect the cable illustrated

-

in Example A to the output o
the Full Wave Bridge

Cable Length

as required

π

Type RFI Filter

≥ Required Current

Transformer :
0 to 28 VAC RMS
for 48 VDC Systems
20 to 48 VAC RMS
for 75 VDC Systems

Shield to Earth Ground

on Supply End Only

23

Example C – Cabling 50 Feet or Greater,
AC Power to Power Supply

DC Volts Out

NOTE:
Connect the cable illustrated
in Example A to the output of
the Power Supply

Shielded Twisted Pair

(Wire Size from

IMS Driver Supply Cable AWG Table)

To Cable A

-

+

Power Supply

Cable Length

as required

π

Type RFI Filter

≥ Required Current

120 or 240 VAC

Dependent on
Power Supply

Shield to Earth Ground

on Supply End Only

24

NOTE: These recommendations will provide optimal
protection against EMI and RFI. The actual cable type,
wire gauge, shield type and filtering devices used are dependent
on the customer’s application and system.

IMS Driver Supply Cable AWG Table

1 Ampere (Peak)

Length (Feet)

Minimum AWG

Length (Feet)

Minimum AWG

Length (Feet)

Minimum AWG

Length (Feet)

Minimum AWG

* Use the alternative methods innustrated in
Examples B and C when the cable length is
feet. Also, use the same current rating when the
alternate AC power is used.

10 25 50* 75* 100*
20 20 18 18 16

2 Amperes (Peak)

10 25 50* 75* 100*
20 18 16 14 14

3 Amperes (Peak)

10 25 50* 75* 100*
18 16 14 12 12

4 Amperes (Peak)

10 25 50* 75* 100*
18 16 14 12 12

≥

50

Driver Supply Cable Wir e Size

NOTE: Always use Shielded/Twisted Pairs for the IMS Driver

DC Supply Cable, the AC Supply Cable and the IMS Driver to
Motor Cable.

25

Recommended Cable Configurations:

IMS Driver to Motor

Cable length, wire gauge and power conditioning devices play a major role

in the performance of your IMS Driver and Motor.

NOTE: The length of the DC power supply cable between the IMS Driver

and the Motor should not exceed 50 feet.

Example A demonstrates the recommended cable configuration for the IMS
Driver to Motor cabling under 50 Feet long. If cabling of 50 feet or longer is
required, the additional length can be gained with the cable configuration in
Example B.

Correct AWG wire size is determined by the current requirement plus cable
length. Please see the IMS Driver to Motor Cable AWG Table in this Appendix.

Example A - Cabling Under 50 Feet,
IMS Driver to Motor

Phase A

Phase A

Phase B

Phase B

Ferrite
Beads

Cable Length

less than 50 Feet

Phase A
Phase A
Phase B
Phase B

Two Shielded/Twisted Pairs

(Wire Size from

IMS Driver to Motor Cable AWG Table)

Shield to Earth Ground

on Supply End Only

26

Example B - Cabling 50 Feet or Greater,
IMS Driver to Motor

Phase A

Phase A

Phase B

Phase B

Ferrite

Beads

Cable Length

50 Feet or greater

Two Shielded/Twisted Pairs

(Wire Size from

IMS Driver to Motor Cable AWG Table)

Common Mode
Line Filters (2x)

Phase A

Phase A

Phase B

Phase B

*L ≈ 0.5 MH

* 0.5 MH is a typical starting point for the
Common Mode Line Filters. By increasing
or decreasing the value of L you can set the
drain current to a minimum to meet your requirements.

Shield to Earth Ground

on Supply End Only

27

1 Ampere (Peak)

Length (Feet)

Minimum AWG

IMS Driver to Motor Cable AWG Table

10 25 50* 75* 100*

20 20 18 18 16

Minimum AWG

Length (Feet)

5 Amperes (Peak)

10 25 50* 75* 100*
16 16 14 12 12

2 Amperes (Peak)

Length (Feet)

Minimum AWG

3 Amperes (Peak)

Length (Feet)

Minimum AWG

4 Amperes (Peak)

Length (Feet)

Minimum AWG

NOTE: These recommendations will provide optimal
protection against EMI and RFI. The actual cable type,
wire gauge, shield type and filtering devices used are dependent on
the customer’s application and system.

NOTE: Always use Shielded/Twisted Pairs for the IMS Driver

DC Supply Cable, the AC Supply Cable and the IMS Driver to
Motor Cable.

6 Amperess (Peak)

10 25 50* 75* 100*

20 18 16 14 14

10 25 50* 75* 100*

18 16 14 12 12

10 25 50* 75* 100*

18 16 14 12 12

Length (Feet)

Minimum AWG

Length (Feet)

Minimum AWG

* Use the alternate method illustrated in Example B
when cable length is

10 25 50* 75* 100*
14 14 14 12 12

7 Amperess (Peak)

10 25 50* 75* 100*
12 12 12 12 12

≥

50 feet.

Driver to Motor Supply Cable Wire Size

28

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WARRANTY

TWENTY-FOUR (24) MONTH LIMITED WARRANTY

Intelligent Motion Systems, Inc. (“IMS”), warrants only to the purchaser of the Product
from IMS (the “Customer”) that the product purchased from IMS (the “Product”) will be free
from defects in materials and workmanship under the normal use and service for which the
Product was designed for a period of 24 months from the date of purchase of the Product by
the Customer. Customer’s exclusive remedy under this Limited Warranty shall be the repair
or replacement, at Company’s sole option, of the Product, or any part of the Product,
determined by IMS to be defective. In order to exercise its warranty rights, Customer must
notify Company in accordance with the instructions described under the heading “Obtaining
Warranty Service.”

This Limited Warranty does not extend to any Product damaged by reason of alteration,
accident, abuse, neglect or misuse or improper or inadequate handling; improper or
inadequate wiring utilized or installed in connection with the Product; installation, operation
or use of the Product not made in strict accordance with the specifications and written
instructions provided by IMS; use of the Product for any purpose other than those for which
it was designed; ordinary wear and tear; disasters or Acts of God; unauthorized attachments,
alterations or modifications to the Product; the misuse or failure of any item or equipment
connected to the Product not supplied by IMS; improper maintenance or repair of the Product;
or any other reason or event not caused by IMS.

IMS HEREBY DISCLAIMS ALL OTHER WARRANTIES, WHETHER WRITTEN OR
ORAL, EXPRESS OR IMPLIED BY LAW OR OTHERWISE, INCLUDING WITHOUT
LIMITATION, ANY WARRANTIES OF MERCHANTABILITY OR FITNESS FOR ANY
PARTICULAR PURPOSE. CUSTOMER’S SOLE REMEDY FOR ANY DEFECTIVE
PRODUCT WILL BE AS STATED ABOVE, AND IN NO EVENT WILL THE IMS BE LIABLE
FOR INCIDENTAL, CONSEQUENTIAL, SPECIAL OR INDIRECT DAMAGES IN
CONNECTION WITH THE PRODUCT.

This Limited Warranty shall be void if the Customer fails to comply with all of the terms set
forth in this Limited Warranty. This Limited Warranty is the sole warranty offered by IMS with
respect to the Product. IMS does not assume any other liability in connection with the sale of
the Product. No representative of IMS is authorized to extend this Limited Warranty or to
change it in any manner whatsoever. No warranty applies to any party other than the original
Customer.

IMS and its directors, officers, employees, subsidiaries and affiliates shall not be liable for
any damages arising from any loss of equipment, loss or distortion of data, loss of time, loss
or destruction of software or other property, loss of production or profits, overhead costs,
claims of third parties, labor or materials, penalties or liquidated damages or punitive damages,
whatsoever, whether based upon breach of warranty, breach of contract, negligence, strict
liability or any other legal theory, or other losses or expenses incurred by the Customer or
any third party.

OBTAINING WARRANTY SERVICE

Warranty service may obtained by a distributor, if the Product was purchased from IMS by
a distributor, or by the Customer directly from IMS, if the Product was purchased directly
from IMS. Prior to returning the Product for service, a Returned Material Authorization (RMA)
number must be obtained. Complete the form at http://www.imshome.com/rma.html after
which an RMA Authorization Form with RMA number will then be faxed to you. Any questions,
contact IMS Customer Service [phone].

Include a copy of the RMA Authorization Form, contact name and address, and any
additional notes regarding the Product failure with shipment. Return Product in its original
packaging, or packaged so it is protected against electrostatic discharge or physical damage
in transit. The RMA number MUST appear on the box or packing slip. Send Product to:
Intelligent Motion Systems, Inc., 370 N. Main Street, Marlborough, CT 06447.

Customer shall prepay shipping changes for Products returned to IMS for warranty service
and IMS shall pay for return of Products to Customer by ground transportation. However,
Customer shall pay all shipping charges, duties and taxes for Products returned to IMS from
outside the United States.

P.O. Box 457, 370 North Main Street
Marlborough, CT 06447 U.S.A.

Phone: [phone]
Fax: [phone]
Email: [e-mail]
Home Page: www.imshome.com

TECHNICAL SUPPORT

Eastern U.S.

Phone: [phone]
Fax: [phone]
E-mail: [e-mail]

Western U.S.

Phone: [phone]
Fax: [phone]
E-mail: [e-mail]

IMS MOTORS DIVISION

105 Copperwood Way, Suite H
Oceanside, CA 92054
Phone: [phone]
Fax: [phone]
E-mail: [e-mail]

IMS EUROPE GmbH

Hahnstrasse 10, VS-Schwenningen
Germany D-78054
Phone: [phone]
Fax: [phone]

European Sales Management

4 Quai Des Etroits
69005 Lyon, France
Phone: [phone]
Fax: [phone]

German Sales/Technical Support

Phone: [phone]
Fax: [phone]
Email: [e-mail]

IM481H Operating Instructions

Revision 051205