 English |
|
|
|
|
|
|
|
| DRV8886AT Datasheet, PDF (21/40 Pages) Texas Instruments – 2-A Stepper Motor Driver With Integrated Current Sense and AutoTune Technology | |||
| |||
| ◁ |
www.ti.com
7.3.6.2 Mode 2: Mixed Decay for Increasing and Decreasing Current
ITRIP
DRV8886AT
SLVSDO1 â JANUARY 2017
tDRIVE
tOFF
tBLANK
tDRIVE
tOFF
tBLANK
tDRIVE
ITRIP
tBLANK
tDRIVE
tFAST
tOFF
tBLANK
tDRIVE
tFAST
tOFF
Figure 19. Mixed-Mixed Decay Mode
Mixed decay begins as fast decay for a time, followed by slow decay for the remainder of tOFF. In this mode,
mixed decay occurs for both increasing and decreasing current steps.
This mode exhibits ripple larger than slow decay, but smaller than fast decay. On decreasing current steps,
mixed decay settles to the new ITRIP level faster than slow decay.
In cases where current is held for a long time (no input in the STEP pin) or at very low stepping speeds, slow
decay may not properly regulate current because no back-EMF is present across the motor windings. In this
state, motor current can rise very quickly, and requires an excessively large off-time. Increasing or decreasing
mixed decay mode allows the current level to stay in regulation when no back-EMF is present across the motor
windings.
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: DRV8886AT
Submit Documentation Feedback
21
|
▷ |
German
Russian
Spanish
Italian
Polish
Chinese
Japanese
Korean
French
Portuguese