Positioning with smart power
Trinamic Microchips has introduced a single chip solution for positioning and driving bipolar stepper motors. The latest member of its stepper motor product line, the TMC211 targets automotive applications such as air conditioning and motorised locks.
The chip itself integrates a local interconnect network (LIN) compliant bus interface, a positioning controller and motor drive electronics. In networked designs, a single LIN master can address up to 128 TMC211 controlled axes.
While traditional motor designs require a powerful microcontroller, a motor driver IC and extensive software programming, a single TMC211 chip is sufficient to fully control a stepper motor in real time.
The on-chip positioning controller, with automatic ramping and 16-time micro stepping capability, performs all real time critical tasks autonomously. Unlike conventional stepper motor drivers, the TMC211 features a high-level command interface with embedded positioning control as well as an automatic reference search function. Therefore, the host controller is offloaded from the repetitive low-level burden associated with step pulse generation. The chips' bi-directional interface supports diagnostic read out of status and failure conditions such as over-temperature, open load, over-current and under-voltage.
The TMC211 can drive bipolar stepper motors with a coil current of up to 800mA. A current control algorithm ensures very smooth and quiet motor rotation.
Available now priced at 2.00 Euros in high volumes, it comes in a 20 pin SOIC package and operates in the automotive temperature range of -40 degrees C to 125 degrees C. It is also available as a 'bare die.'
A TMC211 evaluation kit will be available at the end of September. The kit consists of a TMC211 evaluation board with USB to LIN interface, stepper motor and software.