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TMC211 DATASHEET (V. 1.04 / January 7, 2005)
5.3.3 Chopper Mechanism
The chopper frequency is fixed as specified in chapter 10.4 AC Parameters on page 55. The TMC211
uses an intelligent chopper algorithm to provide a smooth operation with low resonance. The TMC211
uses internal measurements to derive current flowing through coils. If the current is less than the
desired current, the TMC211 switches a H-bridge in a way that the current will increase. Otherwise if
the current is too high, the H-bridge will be switched to decrease the current. For decreasing two
modes are available, slow decay and fast decay, whereas fast decay decreases the current faster than
slow decay. The figure below shows the chopper behavior.
Figure 13: Different Chopper Cycles with Fast and Slow Decay
Copyright © 2004-2005 TRINAMIC Motion Control GmbH & Co. KG
TRINAMIC [ TRINAMIC MOTION CONTROL GMBH & CO. KG. ]
