SLOSE98A December 2022 – September 2023 DRV8461
PRODUCTION DATA
Mixed decay begins as fast decay for a fixed initial duration of the tOFF time (30% or 60%), followed by slow decay for the remainder of tOFF time. Following points should be considered when selecting mixed decay mode -
This mode exhibits ripple larger than slow decay.
On decreasing current steps, mixed decay settles to the new ITRIP level faster than slow decay.
In cases where current is held at the same level for a long time (no STEP input), or at very low stepping speeds, mixed decay allows the current to stay in regulation when no back-EMF is present across the motor windings.
Fixed 30% or 60% mixed decay schemes can result in repeated patterns in current regulation that fall in the audible frequency range, resulting in a noisy motor operation.