MC33192 Datasheet, PDF (3/12 Pages) Motorola, Inc – MI-Bus Interface Stepper Motor Controller

Freescale SMeCm33i1c9o2nductor, Inc.
GENERAL DESCRIPTION
The MC33192 is a serial stepper motor controller for use in
harsh automotive applications using multiplex wiring. The
MC33192 provides all the necessary four phase drive signals
to control two phase bipolar stepper motors operated in either
half or full step modes. Multiple stepper motor controllers can
be operated on a real time basis at step frequencies up to
200 Hz using a single microcontroller (MCU). A primary
attribute of operation is the utilization of the MI–Bus message
media to provide high noise immunity communication
ensuring very high operating reliability of motor stepping.
The MC33192 is designed to drive bipolar stepper motors
having a winding resistance of 80 Ω at 20°C with a supply
voltage of 12 V. It is supplied in a SO–16L plastic package
having eight pins, on one side, connected directly to the lead
frame thus enhancing the thermal performance to allow a
power dissipation of 0.5 W at 120°C ambient temperature.
Multiple Simultaneous Motor Operation
Several motors can be controlled in a serial fashion, one
after the other, using the same software time base. The time
base determines the step frequency of the motors. A single
motor can be operated at a maximum speed of 200 Hz
pull–in with a duration of 5.0 ms per step. Three motors can
be operated simultaneously using a 68HC05B6 MCU at the
same time base (200 Hz) with about 1.7 ms per step. A
68HC11 MCU can control 4 stepper motors with adequate
program step time. The step frequency must be decreased to
control additional motors. To control eight motors
simultaneously would require the motor speed to be
decreased to 100 Hz producing about 2.0 ms time duration
per step with adequate program time.
MI–Bus General Description
The Motorola Interconnect Bus (MI–Bus) is a serial
push–pull communications protocol which efficiently
supports distributed real time control while exhibiting a high
level of noise immunity.
Under the SAE Vehicle Network categories, the MI–Bus is
a Class A bus with a data stream transfer bit rate in excess of
20 kHz and thus inaudible to the human ear. It requires a
single wire to carry the control data between the master MCU
and its slave devices. The bus can be operated at lengths up
to 15 meters.
At 20 kHz the time slot used to construct the message
(25 µs) can be handled by software using many MCUs
available on the market.
The MI–Bus is suitable for medium speed networks
requiring very low cost multiplex wiring. Aside from ground,
the MI–Bus requires only one signal wire connecting the
MCU to multiple slave MC33192 devices with individual
control.
A single MI–Bus can accomplish simultaneous automotive
system control of Air Conditioning, Head Lamp Levellers,
Window Lifts, Sensors, Intelligent Coil Drivers, etc. The
MI–Bus has been found to be cost effective in vehicle body
electronics by replacing the conventional wiring harness.
Figure 1 shows the internal block diagram of the MC33192
Stepper Motor Controller.
Figure 1. MC33192 Stepper Motor Conroller Block Diagram
Xtal (8)
MI (1)
Oscillator
(640 kHz)
5.0 V
10 k
Divider
Programming
Level Detection
Noise Detector
Bi–Phase
Bi–Phase Program
Programmed
Address
Control
Logic
Divider
5.0 V
5.0 V
Regulator
Latch
Dual Bridge Driver and
Motor Diagnostics
20 Ω
Serial to Parallel Register
20 kHz
18 V
Parallel to Serial Register
Thermal
Shutdown
Status
Encoder
+VCC (7)
Gnd (*)
A11 (3)
A12 (4)
B11 (5)
B12 (6)
NOTE: (*) Pins 2, 9, 10, 11, 12, 13, 14, 15 and 16 are common electrical and heatsink ground pins for the device.
MOTOROLA ANALOG IC DEVICE_FD_oA_rT_MA _{ore Information On This Product,}
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