The Trinamic TMC429 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 TMC429 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 Trinamic TMC429 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 Trinamic TMC429 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 Trinamic TMC429 register simplifies application programming. Read-back option for all internal registers simplifies programming. With its internal position counters, the Trinamic TMC429 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 9-8, page 29). Optionally, the micro step table– common for all motors –can be adapted to motor characteristics to further reduce torque ripple.
The TMC429 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 SPITM 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 TMC429. 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 TMC429 with two additional chip select outputs are available. The TMC429 sends data to the driver chain on demand only, which minimizes
the interface traffic and reduces the power consumption.