Datasheet

TMC4671 Datasheet • IC Version V1.00 | Document Revision V1.03 • 2018-Sept-06
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statements are correct for the velocity biquad filter. Both filters’ sampling times are fixed to the PWM
period.
The velocity target value biquad is configured as a second order low-pass with a cutoff frequency at 200 Hz
- by default at a sampling frequency of 25 kHz. Biquad filters can be activated separately.
4.9.2 Standard Velocity Filter
By using the standard velocity measurement algorithm, the default velocity filter is enabled and can not be
switched off. The standard velocity filter is a low-pass filter with a cutoff frequency of 20 Hz (slope of -20
dB/Decade). In this configuration, a new velocity is calculated at a sample rate of approx. 4369.067 Hz.
This configuration is intended to be used in low-performance applications with a simple position feedback
system like digital Hall sensors.
4.9.3 Feed-Forward Control Structure
The TMC4671 provides a feed-forward control structure for torque target value and velocity target value.
The structure is intended to support controllers at high dynamic input profiles. It can be switched on when
using the advanced PI controller structure. The feed-forward value is calculated with a DT1 (29) element.
Each DT1 element can be parametrized with two parameters.
Figure 29: DT1 Element Structure
Equations:
e = X − int_val (36)
int_val =
Z
e dt (37)
Y = b_1 · e (38)
Info
Tuning of feed-forward control structure is supported by the TRINAMIC TMCL-IDE
wizard.
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