September 2012

Doc ID 8700 Rev 3

1/25

AN1495

Application note

Microstepping stepper motor drive

using peak detecting current control

By Thomas Hopkins

Introduction

Stepper motors are very well suited for positioning applications since they can achieve very

good positional accuracy without complicated feedback loops associated with servo

systems. However their resolution, when driven in the conventional full or half step modes of

operation, is limited by the configuration of the motor. Many designers today are seeking

alternatives to increase the resolution of the stepper motor drives. This application note will

discuss implementation of microstepping drives using peak detecting current control where

the sense resistor is connected between the bottom of the bridge and ground. Examples

show the implementation of microstepping drives with several currently available chips and

chip sets.

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