DRV8880PWPR datasheet(21/50 Pages) TI2

21 / 50 page

TRIP

BLANK

DRIVE

OFF

BLANK

DRIVE

FAST

BLANK

OFF

FAST

DRIVE

BLANK

DRIVE

OFF

BLANK

DRIVE

DRV8880

www.ti.com

SLVSD18C – JUNE 2015 – REVISED AUGUST 2017

Product Folder Links: DRV8880

Submit Documentation Feedback

7.3.5.2 Mode 2: Slow Decay for Increasing Current, Mixed Decay for Decreasing current

Figure 17. Slow/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 only occurs during decreasing current. Slow decay is used for increasing current.

This mode exhibits the same current ripple as slow decay for increasing current, since for increasing current, only

slow decay is used. For decreasing current, the ripple is larger than slow decay, but smaller than fast decay. On

decreasing current steps, mixed decay will settle 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 may require a large off-time. In some cases this may cause a loss

of current regulation, and a more aggressive decay mode is recommended.

DRV8880PWPR Datasheet(PDF) 21 Page - Texas Instruments