© Motorola, Inc., 1997, 2000 AN1624
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Motorola Semiconductor Application Note
AN1624
ITC137 68HC708MP16 Motion Control Development Board
By Jim Gray, Bill Lucas, and Warren Schultz
Introduction
A controller that complements software development tools for the
68HC708MP16 is presented here. It provides motor control functions on
a board that interfaces easily with power stages and emulators. Its
configuration is applicable to ac induction, brush dc, and brushless dc
motors.
Figure 1. ITC137 Development Board
Application Note
AN1624
2 MOTOROLA
Description
A summary of the information required to use motion control
development board number ITC137 is presented as follows.
Discussions of hardware design and software are included under
separate headings.
Function The systems development board shown in Figure 1 is designed to
provide control signals for 3-phase ac induction, brush dc, and 3-phase
brushless dc motors. With the software supplied, it is set up to run ac
induction motors.
Inputs are accepted from switches and a potentiometer on the board or
external RUN/STOP, FORWARD/REVERSE, and SPEED signals. The
speed input is a 0- to +5-volt signal with 0 volts corresponding to 0
speed, and 5 volts producing full speed. RUN/STOP and
FORWARD/REVERSE are logic inputs, with logic lows producing run
and reverse outputs. Hall 1, Hall 2, and Hall 3 inputs are also provided
for connection to brushless dc motors.
The ITC137 motion control development board is designed to run in two
configurations. It will operate on its own with the processor supplied.
With the processor removed, it will connect to an M68HC08MP16
emulatorviaanM68CBL08Acable.Forpurposesofmotioncontrolcode
development, the emulator may be run on either an MMDS08 or
MMEVS08.
The output side of this board connects to an ITC122 or ITC132 power
stage via ribbon cable. Six outputs provide power device control signals
for 3-phase induction or brushless dc motors. Brush dc motors can be
controlled by using either one or two of the three available phases. All
six outputs will sink 20 mA, making them suitable for directly driving opto
couplers in isolated gate drives. A switched +5 volts is also provided to
serve as the B+ power source for opto coupler input diodes. It is turned
off at reset to facilitate orderly power-up and power-down of the gate
drives.
Application Note
Description
AN1624
MOTOROLA 3
Electrical
Characteristics The electrical characteristics in Table 1 apply to operation at 25 degrees
Celsius and unless otherwise specified B+ = 12 volts.
Table 1. Electrical Characteristics
Characteristic Symbol Min Typ Max Units
Power supply voltage
Driving ITC122
Driving ITC32 B+ 7.5
7.5 —
—28
15 Volts
Volts
Power supply voltage +5 4.75 — 5.25 Volts
Minimum logic 1 input voltage VIH — 2.7 — Volts
Maximum logic 0 input voltage VIL — 2.0 — Volts
Quiescent current ICC —80—mA
SPEED input VSPEED — 20 — %/volt
Buffer gain
VTemp
VBus
ISense
AV (VTemp)
AV (VBus)
AV (ISense)
—
—
—
–16.9
2
2
—
—
—
—
—
—
Output sink current — — — 25 mA
Application Note
AN1624
4 MOTOROLA
Figure 2. Schematic
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
64
63
62
61
60
59
58
57
56
55
54
53
52
51
50
49
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
W1
PTB2/ATD2
PTB3/ATD3
PTB4/ATD4
PTB5/ATD5
PTB6/ATD6
PTB7/ATD7
PTC0/ATD8
PTC1/ATD9
VDDAD/VDDAREF
VSSAD
VREFL
VADCAP
PTC2
PTC3
PTC4
PTC5
PTC6
PTD0/FAULT1
PTD1/FAULT2
PTD2/FAULT3
PTD3/FAULT4
PTD4/IS1
PTD5/IS2
PTD6/IS3
PWM1
PWM2
PWM3
PWM4
PWMGND
PWM5
PWM6
PTE0/TCLKA
PTB1/ATD1
PTB0/ATD0
PTA7
PTA6
PTA5
PTA4
PTA3
PTA2
PTA1
PTA0
VSSA
OSC2
OSC1
CGMXFC
VDDA
RST
IRQ1/VPP
PTF5/TxD
PTF4/RxD
PTF3/MISO
PTF2/MOSI
PTF1/SS
PTF0/SPSCK
VSS
VDD
PTE7/TCH3B
PTE6/TCH2B
PTE5/TCH1B
PTE4/TCH0B
PTE3/TCLKB
PTE2/TCH1A
PTE1/TCH0A
U1
MC68HC08MP16
V_buf
2-F7
I_amp
2-C7
Pa_buf
2-C2 Pb_buf
2-F2
Pc_buf
2-D4 C
E
D
R15
24 Ω
R16
10 k
C8
0.1 pF
C9
0.1 pF
AGND
+ 5 V
R17 10 k
GREEN_LED
4-D4
YELLOW_LED
4-C4 FLT1
3-D5
0 = 9600 BAUD
1 = 4800 BAUD
FLT2
3-D5
+ 5 V
R18
10 k
R19
10 k
R20
10 k
FLT3
3-D5
FLT4
3-D6
O
N
M
Atop
4-F2Abot
4-F2
Btop
4-F2 Bbot
4-F2
Cbot
4-F3
Ctop
4-F2
R14
10 k + 5 V
HALL_1
3-D3
HALL_2 HALL_3
3-D3
C7
0.1 pF
R13
10 k
I
K
J
L
Q2
MPSA56
1
2
3
820 Ω
R12
R11
10 k
3
2
1
+5_SWITCHED
4-D3
Q1
2N7000
+ 5 V
VPP
SCI_IN
4-C6
SCI_OUT
4-C5
R9
10 k
V_HI
4-C8
J6
1
PGMR_RESET
4-B5
RESET
SW2
R10
10 k
+ 5 V
C6
0.1 pF 24 Ω
R8
+ 5 V
C5
0.1 pF
DIP5
4-B7
DIP4
4-B7
DIP3
4-B7
DIP2
4-B7
DIP1
4-B7
1N914
D5
1N914
D6
0.1 pF
C3 C4
0.1 pF
MONITOR
4-B6
+ 5 V
OUT GND
NC
8
54
4.9152 MHz
1N914
D3 1N914
D4
R7 10 k
R6 10 k
R4 R5
J4
J3
1
1
+ 5 V
EXT_FOR/REV
4-C4
EXT_RUN/STOP
4-C4
SW4 RUN/STOP
SW3 FOR/REV
+ 5 V
AGND
AGND AGND
EXT_SPD_WIPER
4-C2
Vtmp
2-E5
R1
4.7 k
D2
1N914
D1
1N914
+ 5 V
C1
0.1 pF
J5 R2
5 k C2
0.1 pF
24 Ω
R3
+ 5 V
MONITOR MODE = IN
10 k
10 k
+ 5 V
+ 5 V
+ 5 V
3-E4
OSC1
SPEED
Application Note
Description
AN1624
MOTOROLA 5
Figure 3. Schematic (Sheet 1 of 2)
W2
AGND
+ 5 V
INSERT WIRE FOR
LEM SENSOR USE
R22
4.99 k
R21
2.49 k
Phase A
4-F4
R23
2.49 k
R24
4.64 k R25
2.21 k
C10
0.01 pF +
6
5
–
G
Pa_buf
1-B3
7
U2
MC33204
W3
AGND
+ 5 V
INSERT WIRE FOR
LEM SENSOR USE
R27
4.99 k
R26
2.49 k
Phase B
4-F4 R28
2.49 k
R29
4.64 k R30
2.21 k
C11
0.01 pF +
2
3
–
H
Pb_buf
1-B3
1
U2
MC33204
TP4 TP5
W4
AGND
+ 5 V
INSERT WIRE FOR
LEM SENSOR USE
R32
4.99 k
R31
2.49 k
Phase C
4-F4 R33
2.49 k
R34
4.64 k R35
2.21 k
C12
0.01 pF +
9
10 –
A
Pc_buf
1-B3
8
U2
MC33204
TP6
+
13
12
–14
U2
+ 5 V
+ 5 V
4
11
MC33204
Application Note
AN1624
6 MOTOROLA
Figure 3. Schematic (Sheet 2 of 2)
R39
34.0 k
–
5
6
+Vtmp
1-C2
7
U3
TP1
–
3
2
+1
U3
AGND
R40
1.40 k
+ 5 V
R41
100 ΩR42
174 Ω
11 MC33204
C14
0.1 µF
R38
2.0 k
MC33204
R37
4.7 k
+ 5 V
R36
4.7 k
C13
0.1 pF
Vtemp
4-F5
AGND
10°C TO 125°C
AGND
Isense
4-E5
R43
4.75 k
R44
4.75 k
R44
Rgain
C15
0.01 pF +
13
12
–
F
I_amp
1-B3
14
U3
MC33204
TP2
R45
4.75 k
0.01 pF
C16
AGND
Vbus
4-E5
R46
4.75 k
R47
4.75 k
C17
0.01 pF +
9
10
–
B
V_buf
1-B3
8
U3
TP3
R48
4.75 k
MC33204
+ 5 V
4
Application Note
Description
AN1624
MOTOROLA 7
Figure 4. Schematic
R53
1 k
+ 5 V
C32
470 pF
C31
0.1 µF
HALL_1
1-D6
HALL_2
1-D6
HALL_3
1-D6
R56
1 k
R59
1 k
R54
24 Ω
R55
24 Ω
R57
24 Ω
R58
24 Ω
R60
24 Ω
R61
24 Ω
C28
470 pF
C29
470 pF
C30
470 pF
U6 U6
U6
U6
U6
U6
9834
11 10 1 2
13 12 5 6
HALL3
HALL2
HALL1
GND
+ 5 V
T2
HALL EFFECT INPUTS MC14584BCP
MC14584BCP
MC14584BCP
FLT1
1-B5
FLT2
1-B5
FLT3
1-B5
FLT4
1-B5
S
R
Q
P
RP1
10 k RP1
10 k RP1
10 k RP1
10 k
1111
6543
+ 5 V
Application Note
AN1624
8 MOTOROLA
Figure 5. Schematic (Sheet 1 of 2)
+ 5 V
AGND
C18
1µF
+ 5 V
VR1
IN OUT
GROUND C19 C20 C21 C22
1µF 0.1 µF 0.1 µF 0.1 µF
TP
GND
AGND EXT_SPD_WIPER
1-E2 + 5 V
EXT_FOR/REV
1-E3
EXT_RUN/STOP
1-E2
T1
POWER CONNECTOR
+ 5 V
GND
GND
AGND
SPEED
+ 5 V
REV
RUN
GND
EXTERNAL
CONTROL
RUN/DIRECTION
EXTERNAL
SPEED PORT
DC
INPUT POWER
+ 5 V
C34
0.1 µF
C33
0.1 µFC35
0.1 µFC36
0.1 µFC37
0.1 µFC38
0.1 µF
B+
GND
B+ POWER
T3
CONNECTOR
+5_SWITCHED
1-E6 1
3
5
7
9
11
13
2
4
6
8
10
12
14
OUTPUT CONNECTOR
GND
Cbot
Ctop
Bbot
Btop
Atop
Abot
Atop
Abot
Btop
Bbot
Ctop
Cbot
1-B6
1-B6
1-B6
1-B6
1-B6
1-B7
1
3
5
7
9
11
13
2
4
6
8
10
12
14
2-A1
2-D1
2-B3
15 16
AGND
FEEDBACK CONNECTOR
J2
J1
Phase A
Phase B
Phase C
Vtemp
2-B5
+ 5 V + 5 V + 5 V
R49
470 ΩLED2 YELLOW
POWER
LED1 RED R50
1 k
YELLOW_LED
1-B5
LED3 GREEN
R51
1 k
GREEN_LED
1-A5
+
MC7805AC
D7
1N4002
Vbus
2-D7
Isense
2-A7
+
Application Note
Description
AN1624
MOTOROLA 9
Figure 5. Schematic (Sheet 2 of 2)
SCI_OUT
1-D5
DIP1
1-C3
DIP3
1-C3
DIP5
1-C4
DIP4
1-C4
DIP2
1-C3
1
2
3
4
5
SW1
+ 5 V
1
65432
1CD
2TX→
3 RCD ←
4DTR
5 GND
6DSR
7RTS
8CTS
9RI
1CD
2TX→
3 RCD ←
4DTR
5 GND
6DSR
7RTS
8CTS
9RI
10
9
8
7
6
5
4
3
2
1
11
12
13
14
15
16
17
18
19
20
+ 5 V R63
10 k J7
1
SCI PORT
DB-9 CONNECTOR
P1
MONITOR PORT
DB-9 CONNECTOR
P2
+
+
C27
10 µF
C26 10 µF
SCI_IN
1-D5
+ 5 V
MONITOR
1-D3
R52
10 k 4
56
U5
U5
32
1
MC74HC125
U4
MC145407P
DI3 TX3
RX3
TX2
RX2
TX1
RX1
VSS
C2–
GND
C2+
DO3
DI2
DO2
DI1
DO1
VDD
C1–
VCC
C1+
+ 5 V
+
C25
0.1 µF
C24
10 µF
V_HI
1-E4
+ 5 V C23
10 µF
+
+ 5 V
MC74HC125
MC74HC125
MC74HC125
U5 U5
PGMR_RESET
1-E4
11 12
13
89
10
R62
10 k
+ 5 V + 5 V
14 14
7
7
MC74HC125
U5 U6
MC14584BCP
RP2
10 k RP2
10 k RP2
10 k RP2
10 k RP2
10 k
1111
Application Note
AN1624
10 MOTOROLA
Table 2. Parts List
Designators Quantity Description Manufacturer Part Number
C1–C9, C13, C14,
C20–C22, C25, C31,
C33–C38 22 0.1-µf capacitor Sprague 1C105Z5U104M050B
C10–C12, C15–C17 6 .01-µf capacitor Sprague 1C105Z5U103M050B
C18, C19 2 1-µF electrolytic
capacitor Mepco-Centralab CN15A220K
C23, C24, C26, C27 4 10-µF electrolytic
capacitor Digi-Key Corp. P5272
C28-C30, C32 4 470-pF capacitor Sprague 1C105Z5U471M050B
D1–D6 6 Small signal diode — 1N914
D7 1 General-purpose
diode Motorola 1N4002
J1 1 2 x 7.1o.c jumper
block note 2 Digi-Key Corp. S2011-36-ND
J2 1 2x8 .1o.c. jumper
block note 2 Digi-Key Corp. S2011-36-ND
J3, J4, J5, J7 4 1x3 .1o.c. jumper
block note 3 Digi-Key Corp. S1011-36-ND
J6 1 1x4 .1o.c. jumper
block note 3 Digi-Key Corp. S1011-36-ND
LED1 1 Red LED General Instruments MV5774C
LED2 1 Yellow LED General Instruments MV5374C
LED3 1 Green LED General Instruments MV5474C
P1, P2 2 DB-9 connector
(female) Digi-Key Corp. A2100-ND
Q1 1 Small signal FET
transistor Motorola 2N7000
Q2 1 Small signal PNP
transistor Motorola MPSA56
RP1, RP2 2 10 kΩ, 6-pin, SIP
resistor pack Digi-Key Corp. 770-61R10K-ND
R2 1 5-kΩ variable resistor Clarostat Sensors
and Controls, Inc. 392JB-5k-S
R4–R7, R9, R10,
R11, R13, R14 —— — —
Application Note
Description
AN1624
MOTOROLA 11
R16–R20, R52, R62,
R63 17 10-kΩ resistor Yageo Corp. —
R12 1 820 kΩ resistor Yageo Corp. —
R21, R23, R26, R28,
R31, R33 6 2.49-kΩ resistor 1% Yageo Corp. —
R22, R27, R32 3 4.99-kΩ resistor 1% Yageo Corp. —
R24, R29, R34 3 4.64-kΩ resistor 1% Yageo Corp. —
R25, R30, R35 3 2.21-kΩ resistor 1% Yageo Corp. —
R1, R36, R37 3 4.7-kΩ resistor Yageo Corp. —
R38 1 2.00-kΩ resistor 1% Yageo Corp. —
R39 1 34.0-kΩ resistor 1% Yageo Corp. —
R40 1 1.40-kΩ resistor 1% Yageo Corp. —
R41 1 100-Ω trim
potentiometer Digi-Key Corp. 3386P-101-ND
R42 1 174-Ω resistor 1% Yageo Corp. —
R43–R48 6 4.75-kΩ resistor 1% Yageo Corp. —
R49 1 470-Ω resistor Yageo Corp. —
R50, R51, R53, R56,
R59 5 1-kΩ resistor Yageo Corp. —
R3, R8, R15, R54,
R55 —— — —
R57, R58, R60, R61 9 24-Ω resistor Yageo Corp.
SW1 1 5 POS DIP switch CTS CT2068-ND
SW2 1 SPST push-button
switch NKK AB15AP-FA
SW3, SW4 2 SPST toggle switch NKK A12AH
T1 1 8-screw terminal
connector Phoenix Contact MKDSN 1, 5/8–5,08
T2 1 5-screw terminal
connector Phoenix contact MKDSN 1,5/5–5,08
T3 1 2-screw terminal
connector Phoenix contact MKDSN 1,5/2–5,08
U1, socketed 1 Microprocessor Motorola MC68HC708MP16
Table 2. Parts List (Continued)
Designators Quantity Description Manufacturer Part Number
Application Note
AN1624
12 MOTOROLA
U1X, U1 socket 1 QFP 64-pin socket Prine Distributors FPQ-64-0.8–10A
U2, U3 1 Quad op-amp Motorola MC33204P
U4 1 RS-232
driver/receiver Motorola MC145407P
U5 1 Quad bus driver Motorola MC74HC125P
U6 1 Hex Schmitt trigger Motorola MC14584BCP
VR1 1 Voltage regulator Motorola MC7805ACT
OSC1 1 4.9152-MHz oscillator Digi-Key Corp./CTS CTS156-ND
GND, GND, AGND 3 Test point black Components Corp. TP-104-01-00
Atop, Btop, Ctop,
TP1, TP5, TP6 6 Test point red Components Corp. TP-104-01-02
Abot, Bbot, Cbot,
TP2, TP3, TP4, VPP 7 Test point yellow Components Corp. TP-104-01-04
No designator 1 4-40 x 1/4-inch screw
for VR1 ——
No designator 1 4-40 nuts for VR1 — —
No designator 5 Shorting jumpers
for J3–J7 Digi-Key Corp. 929955-06-ND
No designator 6 Self-stick rubber feet — —
ITC137 1 PC board — —
Table 2. Parts List (Continued)
Designators Quantity Description Manufacturer Part Number
Application Note
Pin-by-Pin Description
AN1624
MOTOROLA 13
Pin-by-Pin Description
Inputs and outputs are grouped into six connectors.
Control signal inputs are located on screw connector T1. They are
optional external interfaces that include a provision to power the board
with +5 volts if the B+ input on connector T3 is not used. Screw
connector T2 contains three Hall sensor inputs, a +5-volt connection for
the Hall sensors, and a ground. B+, if used instead of the +5-volt input,
is supplied through screw connector T3. It will accept power supply
voltages from 7.5 to 28 volts when driving an ITC122 power stage, and
7.5to 15 volts when driving an ITC132.Thelowervoltage limit for driving
the ITC132 comes from the need to supply more current from the 5-volt
bus to drive opto-coupled inputs.
Ribbon connector J1 contains six outputs for driving a power stage and
a switched 5-volt power line. Feedback signal inputs are located on
ribbon connector J2, where there is provision for temperature, bus
voltage, and current sense feedback signals.
There is also a DB-9 connector for RS-232 serial port communications
and a DB-9 connector for monitor mode. Ribbon connector pinouts are
shown in Figure 6.
Figure 6. Connector Pinouts
1
3
5
7
9
11
13
2
4
6
8
10
12
14
1
3
5
7
9
11
13
2
4
6
8
10
12
14
15 16
GND
GND
GND
GND
GND
GND
Vbus
Isense
PHASE A
PHASE B
PHASE C
NC
NC
Vtemp
AGND
AGND
ATOP
ABOT
BTOP
BBOT
CTOP
CBOT
GND
+ 5 V
+ 5 V
GND
GND
GND
GND
GND
OUTPUT FEEDBACKTOP VIEW
J1
J2
Application Note
AN1624
14 MOTOROLA
B+ Connector T3
B+ B+ is one of two possible power supply connections. The board either
requires a power supply on this input or a +5-volt supply on connector
T1, not both. For operation with an ITC122 power stage, the B+ input
voltage range is 7.5 to 28 volts dc. For operation with an ITC132 power
stage, it is 7.5 to 15 volts dc.
GND The GND terminal on this connector is intended as the return for power
supply B+.
Input Connector
+5 This input is an alternate input to B+. If it is used, no connection to B+ is
required.
GND There are multiple ground connections. The one adjacent to +5 is
intended as the +5-volt return.
AGND An analog ground for the speed control input is labeled AGND.
SPEED This input can be used to control motor speed with an external 0- to 5-
volt analog signal. Zero volts corresponds to 0 speed and 5 volts to full
speed. To use it, jumper J5 needs to be moved to the external position,
which disables the on-board speed control potentiometer. As shipped,
J5 is set to control speed from the potentiometer.
REV This is an external logic input that reverses the motor when it is
grounded. To use it, jumper J3 needs to be moved to the external
position, which disables the on-board FORWARD/REVERSE switch. As
shipped, J3 is set to control direction from the switch.
RUN Thisisanexternallogicinputthatenablesthemotorwhenit isgrounded.
To use it, jumper J4 needs to be moved to the external position, which
disablestheon-boardRUN/STOPswitch.Asshipped,J4issettocontrol
run/stop from the switch.
Application Note
Pin-by-Pin Description
AN1624
MOTOROLA 15
Hall Connector T2
HALL 1, HALL 2,
HALL 3 These inputs are intended to receive open collector Hall sensor outputs
from brushless dc motors. They are buffered with Schmitt triggers and
filtered for noise immunity.
+5 This connection is for +5 volts that the board supplies to Hall sensors in
a brushless dc motor.
GND GND on this connector is the Hall sensor ground.
Feedback
Connector J2
ISense Pin 15 of feedback connector J2 is a current sense input. It is connected
to A/D channel ATD3 through a gain of 2 non-inverting amplifier.
VBus Pin 13 of connector J2 is a motor bus voltage input. It is connected to
A/D channel ATD2 through a gain of 2 non-inverting amplifier.
VTemp Pin 12 on connector J2 is a temperature sense input. It is connected to
an amplifier that is designed to translate the forward voltage of a diode
into a usable A/D voltage. The output of this amplifier is connected to
A/D channel ATD1.
AGND Pins 14 and 16 are tied to AGND, which is a ground for analog circuits.
This ground is routed such that all of the analog returns connect with
digital ground at just one point.
Phase Voltage
Feedback Phase feedback signals phase A, phase B, and phase C are also
included on feedback connector J2. They are located on pins 2, 4,
and 6. When used with an ITC122 power stage, a divided down phase
voltage appears at these pins. With an ITC132 power stage, no signals
appear at these pins unless they are supplied by the user.
Application Note
AN1624
16 MOTOROLA
Output
Connector J1
Switched +5 Pins 1 and 3 are connected to the 5-volt bus through a switch that is
open at reset. The resulting switched 5 volts can be used to power input
diodes in opto-coupled gate drives, such as the ones found in ITC132
powerstages.Its usefacilitates orderlypower-upandpower-downofthe
gate drives.
GND Pins 5, 7, 9, 11, 13, and 14 are tied to ground. They provide a return for
the switched +5 and are used to provide noise isolation between output
lines in a ribbon cable.
Atop —Cbot Outputs are located on pins 2, 4, 6, 8, 10, and 12. They provide control
signals for three phases of half-bridge configured output transistors and
are set up in an active low configuration. They have the current sinking
capability to drive opto-coupled power stages such as an ITC132.
SCI Port DB-9
Connector This DB-9 connector is set up for RS-232 communication with personal
computers. It has standard RS-232 pinouts. When connected to a serial
port on a personal computer, it can be used to allow keyboard control of
motor drive functions.
Monitor Mode
DB-9 Connector The monitor mode DB-9 connector is included to support background
debug for the HC708MP16.
Test Points
TP1–TP3 Test points TP1, TP2, and TP3 provide access to buffered feedback
signals for temperature, motor bus current, and motor bus voltage.
These voltages are seen by A/D converter inputs ATD1, ATD3, and
ATD2. The temperature feedback voltage can be calibrated with
potentiometer R18.
TP4–TP6 Test points TP4, TP5, and TP6 provide access to buffered feedback
signals from feedback connector J2 pins 2, 4, and 6.
Application Note
Pin-by-Pin Description
AN1624
MOTOROLA 17
GND and AGND These test points are provided to facilitate grounding test instruments.
Outputs All six outputs and a ground are also available as test points. They are
connected in parallel with the outputs on ribbon connector J1.
Switches
SW1 SW1 (switch 1) is a 5-position DIP switch that enables modulation
parameters to be changed while a motor is running. Switch positions are
illustrated in Figure 7. Position 1 sets full modulation for either 60 or
120Hz. Position 2selectseither sine waveorthird harmonic pulse-width
modulation (PWM). Positions 3, 4, and 5 select PWM frequency per
Table 3 in the software section of this application note.
SW2 SW2 (switch 2) is a push-button switch located on the right-hand edge
of the board. It is labeled RESET. It resets the processor and turns off
the switched 5 volts supplied on output connector J1.
Figure 7. Switch 1
3RD HARMONIC PWM
120 Hz FULL MODULATION
60 Hz FULL MODULATION
SINE WAVE PWM
12345 PWM RATE
(SEE TABLE 3)
ON
Application Note
AN1624
18 MOTOROLA
Potentiometers
R2 R2, labeled SPEED ADJUST, is the speed control potentiometer. It
controls motor speed unless jumper J5 is set to the external position or
control is taken over by the SCI port.
R41 R41 is a small potentiometer that is used for adjusting the analog signal
that represents temperature. Setting the voltage at test point TP1 to
1 volt at 25 degrees Celsius with this potentiometer is the recommended
default calibration.
Expanded I/O There are a number of blank pads located at the top of the printed circuit
board. They are included to allow a user to expand the capability of the
system with a prototype board. The connections are described from left
to right.
APad A is connected to the output of a non-inverting amplifier that has its
input at feedback connector J2 pin 6. This amplifier has a gain of 1.5. Its
output also connects to the processor’s analog input ATD6.
BPad B provides access to the bus voltage feedback signal. It is
connected to the output of a non-inverting amplifier that has a gain of 2
and its input at feedback connector J2 pin 13. This signal also ties to the
processor’s analog input ATD2.
CPad C is connected to the processor’s analog ATD7 input pin.
DPad D is connected to the processor’s analog ATD9 input pin.
EPad E is connected to the processor’s analog ATD8 input pin.
FPad F provides access to the bus current feedback signal. It is
connectedto theoutputof anon-invertingamplifier that hasa gain oftwo
and its input at feedback connector J2 pin15. This signal also ties to the
processor’s analog input ATD3.
Application Note
Pin-by-Pin Description
AN1624
MOTOROLA 19
GPad G is connected to the output of a non-inverting amplifier that has its
input at feedback connector J2 pin 2. This amplifier has a gain of 1.5. Its
output also connects to the processor’s analog input ATD4.
HPad H is connected to the output of a non-inverting amplifier that has its
input at feedback connector J2 pin 4. This amplifier has a gain of 1.5. Its
output also connects to the processor’s analog input ATD5.
IPad I is connected to the processor’s MISO pin.
JPad J is connected to the processor’s SS output pin.
KPad K is connected to the processor’s MOSI pin.
LPad L is connected to the processor’s SPSCK output pin.
MPad M is connected to the processor’s IS3 input pin. This signal is pulled
up to +5 volts through a 10-kΩ resistor.
NPad N is connected to the processor’s IS2 input pin. This signal is pulled
up to +5 volts through a 10-kΩ resistor.
OPad O is connected to the processor’s IS1 input pin. This signal is pulled
up to +5 volts through a 10-kΩ resistor.
PPad P is connected to the processor’s FAULT4 input pin. This signal is
pulled to logic ground through a 10-kΩ resistor.
QPad Q is connected to the processor FAULT3 input pin. This signal is
pulled to logic ground through a 10-kΩ resistor.
RPad R is connected to the processor’s FAULT2 input pin. This signal is
pulled to logic ground through a 10-kΩ resistor.
SPad S is connected to the processor’s FAULT1 input pin. This signal is
pulled to logic ground through a 10-kΩ resistor.
Application Note
AN1624
20 MOTOROLA
+5 Four pads labeled +5 provide +5 volts from the on-board 7805 regulator
for prototype circuitry.
GND Four pads labeled GND provide logic ground for use by additional
prototype circuitry.
B+ Two pads labeled B+ are connected to the B+ power input on terminal 3.
Application Example
An application example, shown in Figure 8, illustrates system
connections to an ITC132 power stage and an induction motor. This
arrangement can run stand alone or the ITC137 can be connected to an
MMDS08 for code development. The two boards are designed such that
the drive and feedback ribbon connectors line up. Ribbon cables are
supplied. Once they are plugged in, it is only a matter of connecting
power supplies and the motor to get a system up and running.
A 3-phase, center-aligned, sine wave pulse-width modulation (PWM)
signal is generated by the ITC137. Speed is controlled by the frequency
and amplitude of this signal, while direction is determined by phase-to-
phase sequence. Systems parameters are easily changed, while a
motor is running. Switch 1 on the ITC137 board will change PWM rate,
modulation type, and full modulation frequency. If the RS-232
communications interface is used, terminal mode operation includes
inputs for boost voltage and several types of space vector modulation.
Application Note
Design Considerations
AN1624
MOTOROLA 21
Figure 8. Application Example
Design Considerations
The ac induction motor drives are relatively complex internal to the
processor in terms of code, processing power, and the PWM timer’s
hardware. Brushless dc motor drives tend to be more complex external
to the processor, particularly with regard to noise management of the
sensor inputs. A number of design considerations that cover operation
with both types of motors are discussed here.
Sensor Inputs For brushless motors that use sensor inputs for commutation, noise
immunity of the sensor inputs is a key design consideration. Noise on
these inputs can be particularly troublesome, since commutating to the
wrong state can jerk the motor and increase power dissipation. To
facilitate noise robust sensor inputs, Schmitt triggers have been placed
between the Hall sensor input connector and the processor. Hysteresis
makes the Schmitt trigger significantly more robust than using input
ports directly. In addition, these signals are filtered with 100 ns single
MC68HC708MP16
MOTION CONTROL
DEVELOPMENT BOARD
HIGH-VOLTAGE
MICRO-TO-MOTOR INTERFACE
GND
B+ 7.5 Vdc – 15 Vdc
DRIVE
FEEDBACK
HV RAIL
RTN
Aout
Bout
Cout
+ 18 V
RTN
RTN
+18 Vdc
INDUCTION MOTOR
+ 320 Vdc
MOTOROLA
ITC137 MOTOROLA
ITC132
Application Note
AN1624
22 MOTOROLA
pole filters. Using relatively low value pullup resistors, on the order of
1 kΩ, provides an additional measure of noise immunity.
Theway that the code is writtenalsohasan important influence on noise
robustness. Since the sequence of commutation is known, based upon
the state of the forward/reverse input, it is relatively easy to detect an
out-of-sequence Hall sensor input. Generally speaking, when this
occurs it is desirable to turn all the power transistors off until a valid Hall
code is received.
Lockout Especially on a machine that will be used for code development, it is
desirabletopreventsimultaneousconductionofupper-andlower-power
transistors in the same phase. This feature is built into the
HC708MP16’sPWM timer. Once the timer has been initialized correctly,
simultaneous conduction of a top and bottom output transistor in the
same phase is locked out. Code errors that occur after initialization is
completed will, therefore, not destroy power stage output transistors by
turning on the top and bottom of one half bridge simultaneously. This
arrangement also prevents simultaneous conduction in the event of a
noise induced software runaway.
Dead Time In induction motor drives, providing dead time between turn-off of one
output transistor and turn-on of the other output transistor in the same
phase is an important design consideration. Dead time is also a feature
that is built into the HC708MP16’s PWM timer. It is programmable, to
accommodate a variety of gate drives and output transistors. In the
software 2 µs of dead time has been selected for operation with ITC132
power stages.
Power-Up/
Power-Down When power is applied or removed, it is important that top and bottom
output transistors in the same phase are not turned on simultaneously.
Since the outputs are low when unpowered, sequencing is important in
opto-coupled drives where the ITC137 output directly drives opto
couplers. To ensure proper sequencing, a switched +5 is provided for
sourcing drive current to the opto’s. This supply is held off until RESET
occurs and input voltage is high enough for safe operation. Connection
Application Note
Demonstration Software
AN1624
MOTOROLA 23
to an opto input is illustrated in Figure 9. It applies to operation with an
ITC132 power stage.
Figure 9. Connection to an Opto-Coupled Output Stage
Grounding Last but not least, board layout is an important design consideration. In
particular, how grounds are tied together influences noise immunity. In
ordertomaximizenoiseimmunity,atwosectiondigitalgroundplaneand
a separate analog ground trace that intersects the digital ground plane
at just one point are used. The digital ground plane (GND) is common to
the power supply return and serves as a general-purpose ground. It is
sectioned around the PWM timer’s outputs to keep the relatively high
return current associated with the outputs from flowing all over the
board. An analog ground (AGND) ties the speed control input return and
op amp signal grounds together before connecting with digital ground at
only one point. AGND also runs as a separate trace to pins 14 and 16 of
FEEDBACK connector J2.
Demonstration Software
Software included with the ITC137 motion control development board
provides basic ac induction motor control. It is intended to use with an
ITC132 high-voltage micro-to-motor interface, as shown in Figure 8.
Firmware for this application is programmed into the MC68HC708MP16
for immediate use. Source code is also provided on diskette. Open loop
volts per Hertz drive from 0 to 120 Hz and PWM rates of 1800 to
28,800 Hz are supported. Other options include sine, third harmonic
injection,or space vector modulation waveforms, full modulation at60or
SWITCHED + 5 V
Atop
5 V
Atop 10 k
1N914
180 Ω
ISO1
HCPL0453
+ 18 V 2.2 ΩMUR1100E
5.6 k
10 µF
MC33153
Application Note
AN1624
24 MOTOROLA
120 Hz, run/stop and direction control. Two different operating modes
are possible with the supplied software: stand alone mode and terminal
mode.
Stand Alone Mode When the ITC137 is initialized after reset, it is operating in stand alone
mode. In this mode, all options (speed, direction, etc.) are read from
controls on the board. Since the software ensures coordination of the
actual changes in PWM, voltage, etc., changes may safely be made in
real time while driving a motor. One exception to this is if the motor load
has a large amount of inertia. In this case, the rate of speed change
allowedbythesoftwaremaynot beslow enoughto preventregeneration
of excessive dc bus voltage.
User settings are:
• SPEED,or drivefrequency, isdetermined byspeedpotentiometer
R2. Frequency may be set from 0 to 120 Hz in 1-Hz increments.
Large changes are not instantly applied; instead a slow ramp to
the new setting is implemented.
• FORWARD/REVERSE sets the drive direction. When direction is
reversed, speed is ramped down to 0 then ramped up to the
current speed setting in the new direction.
• RUN/STOP allows speed to be forced to 0. Speed is ramped to 0
when stop is selected, then rammed up to the current speed
setting when the switch is returned to RUN.
• DIP SWITCH SETTINGS — Additional operating options are
controlled by a 5-position DIP switch, SW1. Position 1 determines
the frequency of 100 percent voltage modulation, OFF for full
voltage at 60 Hz, and ON for full modulation at 120 Hz. Position 2
determinesthewaveform,OFF forsine, andON forthirdharmonic
injection. PWM rates are determined by positions 3, 4, and 5 as
shown in Table 3.
Application Note
Demonstration Software
AN1624
MOTOROLA 25
Terminal Mode The ITC137 serial port, labeled SCI, is also enabled and monitored for
activity. A terminal or terminal emulation software running on a personal
computer (PC) will communicate with this port. Any basic serial
communications software that is set for 9600 baud, eight data bits, no
parity, and one stop bit, will work.
Whencommanded todo soviathe terminal,theITC137 canbe switched
to terminal mode, where all control is by keyboard entries. This can be
done in real time without disturbing motor drive parameters. When
terminal mode is activated, it uses the ITC137 hardware settings as
defaults, and when deactivated, settings revert to the hardware.
To connect the ITC137 to an IBM-compatible PC, follow these steps:
1. With power removed from the ITC137 and the PC off, connect a
9-connector straight through cable from the ITC137 connector
labeled SCI to the COM1 or COM2 serial port of the PC. PC serial
ports are wired as DTE (data terminal equipment) and the ITC137
SCI port is wired as DCE (data communications equipment). This
is why a 9-conductor cabled wired straight through must be used.
Do not use a null modem cable.
2. Restore power to the ITC137 and PC.
Table 3. PWM Rates
DIP 3 DIP 4 DIP 5 PWM Rate
On On On 2000
On On Off 4000
On Off On 8000
On Off Off 12,000
Off On On 16,000
Off On Off 18,000
Off Off On 20,000
Off Off Off 22,000
Application Note
AN1624
26 MOTOROLA
3. If you are using DOS-based communications software such as
ProComm, set the COM port to COM1 or COM2 depending on
which PC port you have cabled to the ITC137. Set the baud rate
to 9600, the number of data bits to eight, the number of stop bits
to one and the parity to none. Set the duplex to full duplex.
4. If you are using Windowsor Windows 95, a terminal program is
included in the accessories. Start the terminal program, open the
setting pulldown menu, and select communications. Set the
options as listed in step 3.
5. ResettheITC137board.Ifconnectedandconfiguredproperly,the
terminal will display software version information and the top level
command menu shown in Figure 10.
Keyboard activity will have no effect until the control mode command is
used to set terminal mode. In this mode, further inputs from the ITC137
hardware controls are ignored. The initial settings will be identical to the
hardware settings at the time control is transferred. When control is
returned to stand alone mode, settings will revert to the hardware
settings, including a gradual ramp to the speed control potentiometer
setting. Thus transfer between the two modes may be made while
driving a motor.
Figure 10. Terminal Display
ProComm is a trademark of Datastorm Technologies, Inc.
Windows and Windows 95 are registered trademarks of Microsoft Corporation.
Application Note
Terminal Mode Main Menu
AN1624
MOTOROLA 27
Terminal Mode Main Menu
The main menu, shown in Figure 10, allows the following command
options. Note that commands are executed when followed by an ENTER
keystroke.
Control mode (c)
Chooses between stand alone mode, with ITC137 board controls and
terminal mode with all control via terminal commands
Frequency (f)
Sets drive frequency from 0 to 120 Hz
Voltage (v)
Temporarily overrides the normal volts per Hertz setting with a new
voltage. Voltage will change instantly.
WARNING: Large voltage jumps or setting a large voltage at a low frequency can
damage power transistors.
PWM rate (p)
Chooses a PWM carrier frequency between 1800 and 28,800 Hz
Direction (d)
Selects forward or reverse
Run/Stop (r)
Selects run or stop
Boost (b)
Chooses a low-frequency voltage boost of up to 20 percent
Set full modulation frequency(s)
Selects a 100 percent modulation point of 60 Hz or 120 Hz. Voltage
will change instantly between these two slopes.
WARNING: Note that large voltage jumps can be hazardous to power stages.
Application Note
AN1624
28 MOTOROLA
Modulation type (m)
Chooses between sine, sine plus third harmonic injection or space
vector modulation (SVM) waveforms. In order to experiment with any
SVM modulation type containing V0 nulls with an ITC132 power
stage, the bootstrap circuit should be modified. At least 220 µF of
additional bootstrap capacitance on each phase is needed for
adequate hold up time. Pads are provided on ITC132 boards for this
purpose. Therefore, it is not advisable to select type V0; or V0, V7; or
V7, V0 from this menu when using an unmodified ITC132 board.
Analog readings (a)
Enables or disables on-screen display of bus voltage, bus current,
and temperature information
Software
Functional
Overview
Thecorefunctionofthedemonstrationcode istosynthesize threephase
waveforms for variable frequency drive of ac induction motors. This task
is simplified greatly by the 6-channel motor control PWM unit on the
MC68HC807MP16. In general, waveforms are synthesized by looking
up values in a table for each point along a curve and then converting
these values to PWM duty cycles. The repetition rate, or carrier
frequency, determines how many data points define the curve. Drive
frequency, typically 0 to 120 Hz, is determined by how rapidly the
microprocessor steps through the table values.
The timebase for this process is the rate at which the PWM unit
interruptsthe HC08 CPU. IfthePWMunit is configured tointerruptevery
cycle, this rate is identical to the carrier frequency. It is common practice
toservice the PWM unitlessoftenthan this at highercarrierfrequencies.
This entire process is performed three times upon each interrupt to
create three waveforms that are each offset 120 degrees.
Only about 1800 bytes of code are needed for this basic operation. The
user terminal interface, additional demonstration features, and factory
test routines use about 11,000 bytes. The code is modular and written in
C language (except for the SINESCALE routine), in order to encourage
experimentation and reuse. A brief summary of each module is listed as
follows. Consult and C source code for complete details.
Application Note
Terminal Mode Main Menu
AN1624
MOTOROLA 29
MAIN
• Initializes PWM and SCI units
• Resets communication, A/D data, and waveform data table
pointers
• Enables interrupts for PWM and communication
• Enters SCAN loop
PWM
• PWM interrupt handler
• Services COP
• Passes data table pointer to QUADZ for each phase
• Loads PVALX registers from global RAM value pwmmod
• Exchanges two phases if reverse direction is set
• Maintains waveform data table pointers
• Sets PWM unit LDOK bit
QUADZ
• Accepts waveform data table pointer
• Translates full waveform pointer into quadrant pointer
• Selects sine or third harmonic injection according to settings
• Calls SINSCALE to scale table value with global RAM value
vscale
• Modifies global RAM value pwmmod
SINSCALE
• Accepts waveform data and scaling value
• Scales with 24-bit accuracy
• Returns integer formatted for use in PVALX registers
Application Note
AN1624
30 MOTOROLA
SVM
• Accepts waveform data table pointer
• Calculates SVM time segments via CALCULATE function
• Modifies PWM PVALX registers
CALCULATE
• Calculates times for SVM modulation
SCAN
• Scans hardware for speed, PWM, etc., settings
• Scans serial communication buffer for commands via GETCH
• Parses commands, sets control flags
• Calls RECALC to execute setting changes
• Calls MENU to reflect changes back to terminal user
RECALC
• Recalculatescorrect PWM modulus,loadfrequency, and interrupt
frequency
• Recalculates correct data table pointer increment value
• Updates PWM registers and RAM variables coherently with
interrupt mask
MENU
• Transmits command menus and current settings to terminal user
RECEPT
• SCI interrupt handler writes to buffer
• Maintains pointer
PUTCHAR
• SCI transmit
GETCH
• Parses input string in buffer
Application Note
Terminal Mode Main Menu
AN1624
MOTOROLA 31
Software
Development The ITC137 may be used in an emulation environment with Motorola
MMDS08or MMEVS08 developmenttools.Executable code inS-record
formatis includedonthe sourcecodediskette. Thedevelopmentsystem
flex cable can be connected directly to the ITC137 without the use of a
target head adapter by following these steps:
1. Ensureall power is removed from the development tool (MMDS08
or MMEVS08), the ITC137 board, and the ITC132 board.
2. Remove the MC68HC708MP16 processor on the ITC137 board
from its socket.
3. Attached the development tool M68CBL05C flex cable directly to
the ITC137 using the headers next to the processor’s socket.
4. Restore power to the development tool and the ITC137 board.
CAUTION: Do not restore power to the ITC132 high-voltage rail at this point.
5. Following development tool instructions, download the
demonstration code S records or code of your own creation and
run it.
6. Using an oscilloscope, probe the PWM top and bottom output test
points provided on the ITC137.
7. Restore power to the motor rail only after verifying that ITC137
output waveforms are correct.
CAUTION: Power must be removed in the exact reverse of this sequence when
shutting down or power stage IGBTs may be damaged.
Additional
Precautions It is very important to note that emulator operations such as stopping
emulation or setting breakpoints can over-stress power stages. If, for
example, the emulator is stopped in a state that energizes the motor, the
relatively low winding resistance in most ac motors will allow excessive
current to flow. Under these circumstances, it is relatively easy to over-
stress power devices. Any software change, no matter how minor,
should be checked out with the above procedure before applying power
to the motor.
NON-DISCLOSURE AGREEMENT REQUIRED
Application Note
AN1624/D
© Motorola, Inc., 1997, 2000
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including without limitation consequential or incidental damages. "Typical" parameters which may be provided in Motorola data sheets and/or specifications can and do vary in different
applications and actual performance may vary over time. All operating parameters, including "Typicals" must be validated for each customer application by customer's technical experts.
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Conclusion
The ITC137 controller is part of a tool set that facilitates motor drive
development. It allows the 68HC708MP16 processor’s performance to
be verified in many applications without the need for building hardware
or developing software. ITC137 controllers interface with MMDS08 and
MMEVS08 development tools for writing code, with ITC122 and ITC132
power stages for energizing motors and with serial port terminals for
changing motor control parameters real time. In addition, both hardware
designandsource code can be used as references for speeding product
development.
