TMC428_06 Datasheet, PDF (3/58 Pages) List of Unclassifed Manufacturers – Intelligent Triple Stepper Motor Controller with Serial Peripheral Interfaces

TMC428 DATASHEET (v. 2.02 / April 26^th, 2006)
3
2 General Description
The TMC428 is a miniaturized high performance stepper motor controller with a unique price /
performance ratio for both, high volume automotive and for demanding industrial motion control
applications. Once initialized, the TMC428 controls up to three 2-phase stepper motors. Its low price
makes it attractive also for applications, where only one or two stepper motors have to be controlled
simultaneously.
The TMC428 performs all real time critical tasks autonomously. Thus a low cost microcontroller is
sufficient to perform the tasks of initialization, application specific interfacing, and to specify target
positions and velocities. The TMC428 allows on-the-fly change of all motion target parameters also
during motion. Any other parameter may be changed at any time– also during motion –which does not
make sense in any case, but this uniform access to any TMC428 register simplifies application
programming. Read-back option for all internal registers simplifies programming. With its internal
position counters , the TMC428 can perform up to 2²³ steps respectively micro steps fully independent
from the microcontroller. The step resolution– individually programmable for each stepper motor –
ranges from full step (1 ‘’micro step’’ is one full step), half step (2 ‘’micro steps’’ per full step), up to 6
bit micro stepping (64 micro steps per full step) for precise positioning and noiseless stepper motor
rotation (Table 8-8, page 26). Optionally, the micro step table– common for all motors –can be adapted
to motor characteristics to further reduce torque ripple.
The TMC428 has got serial interfaces for communication with the microcontroller and for the stepper
motor drivers. The serial interface for the microcontroller uses a fixed length of 32 bits with a simple
protocol, directly connecting to SPI^TM interfaces. The serial interface to the stepper motor drivers is
flexibly configurable for different types– even from different vendors –with up to 64 bit length for the
SPI daisy chain. TRINAMIC smart power stepper motor drivers TMC236, TMC239 and TMC246,
TMC249 perfectly fit to the TMC428. Without additional hardware, drivers with same serial interface
polarities of chip select and clock signals may be mixed in a single chain. To mix drivers with different
serial interface polarities, additional inverters (e.g. 74HC04, 74HC14) are required. For those driver
chips without serial data output, two additional variants of the TMC428 with two additional chip select
outputs are available. The TMC428 sends data to the driver chain on demand only, which minimizes
the interface traffic and reduces the power consumption.
Hint: Unused reference switch inputs should be pulled to ground (Figure 2-1). With this one can
connect reference switches that connect to +5V resp. +3.3V when pushed. Concerning different
reference switch configurations please refer to Figure 9-3, Figure 9-4, Figure 9-5.
Reference Switch Inputs
(active high)
1K
1K
1K
REF1 REF2 REF3
SS
nSCS_C
nSCS_S
MOSI
µC
SDI_C
TMC428-I /
SDO_S
TMC428-A
SCK
MISO
CLK
SCK_C
SDO_C _CLK
V33
SCK_S
V5 TEST GND ^SDI_S
470
nF
Note: output SDO_C will
nerver be high impedance
100 nF
+5 V
CSN
*
SDI
SDO
TMC23x / TMC24x
SCK
10K
SM#3
*For details concerning electrical connections of
the TMC236 / TMC239 / TMC246 / TMC249
refer to its datasheet.
CSN
*
SDI
SDO
TMC23x / TMC24x
SCK
CSN
*
SDI
SDO
TMC23x / TMC24x
SCK
SM#2
SM#1
Figure 2-1: TMC428 application environment with TMC428 in SSOP16 package
Copyright © 2004-2006, TRINAMIC Motion Control GmbH & Co. KG