DRV8880_15 Datasheet, PDF (12/48 Pages) Texas Instruments – DRV8880 2-A Stepper Motor Driver With AutoTune™

DRV8880
SLVSD18A – JUNE 2015 – REVISED JULY 2015
7 Detailed Description
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7.1 Overview
The DRV8880 is an integrated motor driver solution for bipolar stepper motors. The device integrates two NMOS
H-bridges, current regulation circuitry, and a microstepping indexer. The DRV8880 can be powered with a supply
voltage between 6.5 and 45 V, and is capable of providing an output current up to 2.5 A peak current, 2.0 A full-
scale current, or 1.4 A rms current. Actual operable full-scale and rms current will depend on ambient
temperature, supply voltage, and PCB ground plane size. Between VM = 6.4 V and VM = 4.9 V the H-bridge
outputs are shut down, but the internal logic remains active in order to prevent missed steps.
A simple STEP/DIR interface allows easy interfacing to the controller circuit. The internal indexer is able to
execute high-accuracy microstepping without requiring the processor to control the current level. The indexer is
capable of full step and half step as well as microstepping to 1/4, 1/8, and 1/16. In addition to the standard half
stepping mode, a non-circular 1/2-stepping mode is avaialble for increased torque output at higher motor rpm.
The current regulation is highly configurable, with several decay modes of operation. The decay mode can be
selected as a fixed slow, slow/mixed, mixed, slow/fast, or fast decay. The slow/mixed decay mode uses slow
decay on increasing steps and mixed decay on decreasing steps. Similarly, the slow/fast decay mode uses slow
decay on increasing steps and fast decay on decreasing steps.
In addition, an AutoTune mode can be used which automatically adjusts the decay setting to minimize current
ripple while still reacting quickly to step changes. This feature greatly simplifies stepper driver integration into a
motor drive system.
The PWM off-time, t_OFF, can be adjusted to 10, 20, or 30 µs.
An adaptive blanking time feature automatically scales the minimum drive time with output current. This helps
alleviate zero-crossing distortion by limiting the drive time at low-current steps.
A torque DAC feature allows the controller to scale the output current without needing to scale the analog
reference voltage input VREF. The torque DAC is accessed using digital input pins. This allows the controller to
save power by decreasing the current consumption when not required.
A low-power sleep mode is included which allows the system to save power when not driving the motor.
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