User Manual

TMCM-110-42 Manual 11

5.1.3 TMC428 Motion Controller

The TMC428 is a high-performance stepper motor control IC and can control up to three 2-phase-stepper-

motors (on this module, only one motor can be used). Motion parameters like speed or acceleration are sent

to the TMC428 via SPI by the microcontroller. Calculation of ramps and speed profiles are done internally by

hardware based on the target motion parameters.

5.1.4 TMC246 Motor Driver

The stepper motor driver used on the TMCM-110 module is the TMC246 chip. This driver is very dependable,

because it provides a variety of protection and diagnostic features, which even can be read out by the user

software. Its 16x up to 32x microstepping gives a quiet and precise motor operation. As the power

dissipation of the TMC246 chips is very low no heat sink or cooling fan is needed. The temperature of the

chips does not get too high easily. The coils will be switched off automatically when the temperature or the

current exceeds the limits and automatically switched on again when the values are within the limits again.

5.2 Power Supply

The TMCM-110-42 is equipped with a linear voltage regulator that generates the 5V supply voltage for the

digital components of the module from the motor power supply. So only one supply voltage is needed for

the module. The power supply voltage can be 12..30 V DC. A higher voltage gives higher motor dynamics.

Please note that there is no protection against reverse polarity or too high voltage.

When using supply voltages near the upper limit of 34V, a regulated power supply becomes a must. Please

ensure, that enough power filtering capacitors are provided in the system (470µF or more recommended per

motor), in order to absorb mechanical energy fed back by the motor in stalling conditions.

The power supply should be designed in a way, that it supplies the nominal motor voltage at the desired

maximum motor power. In no case shall the supply value exceed the upper / lower voltage limit. To ensure

reliable operation of the unit, the power supply has to have a sufficient output capacitor and the supply

cables should have a low resistance, so that the chopper operation does not lead to an increased power

supply ripple directly at the unit. Power supply ripple due to the chopper operation should be kept at a

maximum of a few 100mV. This also is important in order to make the users application compatible to any

applicable EMC guidelines.

Therefore we recommend to

a) keep power supply cables as short as possible

b) use large diameter for power supply cables

c) if the distance to the power supply is large (i.e. more than 2 - 6m), use a robust 470µF or larger

additional filtering capacitor located near to the motor driver unit.

5.3 Communication Interface

The communication between the host and the module takes place via its host interface. This can be either

RS232, RS485, IIC or CAN. Please note that the TMCM-110-42 module can only be equipped with one of these

interfaces. Communication with the TMCM-110-42 module is done using TMCL commands. The interface the

module is equipped with is ready-to-use, so there are no external drivers or level shifters necessary.

Please see chapter 3.3.1 for the pin assignments of the interfaces.