TMC5072 DATASHEET (Rev. 1.22 / 2017-MAY-16)
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1.7 coolStep – Load Adaptive Current Control
coolStep drives the motor at the optimum current. It uses the stallGuard2 load measurement
information to adjust the motor current to the minimum amount required in the actual load situation.
This saves energy and keeps the components cool.
Benefits are:
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Energy efficiency
Motor generates less heat
Less or no cooling
power consumption decreased up to 75%
improved mechanical precision
improved reliability
Use of smaller motor
less torque reserve required → cheaper motor does the job
Figure 1.2 shows the efficiency gain of a 42mm stepper motor when using coolStep compared to
standard operation with 50% of torque reserve. coolStep is enabled above 60RPM in the example.
0,9
Efficiency with coolStep
0,8
0,7
0,6
0,5
0,4
0,3
0,2
0,1
0
Efficiency with 50% torque reserve
Efficiency
0
50
100
150
200
250
300
350
Velocity [RPM]
Figure 1.2 Energy efficiency with coolStep (example)
1.8 dcStep – Load Dependent Speed Control
dcStep allows the motor to run near its load limit and at its velocity limit without losing a step. If the
mechanical load on the motor increases to the stalling load, the motor automatically decreases
velocity so that it can still drive the load. With this feature, the motor will never stall. In addition to
the increased torque at a lower velocity, dynamic inertia will allow the motor to overcome
mechanical overloads by decelerating. dcStep directly integrates with the ramp generator, so that the
target position will be reached, even if the motor velocity needs to be decreased due to increased
mechanical load. A dynamic range of up to factor 10 or more can be covered by dcStep without any
step loss. By optimizing the motion velocity in high load situations, this feature further enhances
overall system efficiency.
Benefits are:
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Motor does not loose steps in overload conditions
Application works as fast as possible
Highest possible acceleration automatically
Highest energy efficiency at speed limit
Highest possible motor torque using fullstep drive
Cheaper motor does the job
1.9 Encoder Interfaces
The TMC5072 provides two encoder interfaces for external incremental encoders. The encoders can be
used for homing of the motion controllers (alternatively to reference switches) and for consistency
checks on-the-fly between encoder position and ramp generator position. A programmable prescaler
allows the adaptation of the encoder resolution to the motor resolution. 32 bit encoder counters are
provided.
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TRINAMIC [ TRINAMIC MOTION CONTROL GMBH & CO. KG. ]
