Introduction

The AMIS?30511 is a micro?stepping stepper motor driver for bipolar stepper motors. The chip is connected through I/O pins and a SPI interface with an external microcontroller. The AMIS?30511 contains a current?translation table and takes the next micro?step depending on the clock signal on the “NXT” input pin and the status of the “DIR” (=direction) register or input pin. The chip provides a so?called “speed and load angle” output. This allows the creation of stall detection algorithms, step loss detection, and control loops based on load?angle to adjust torque and speed. It is using a proprietary PWM algorithm for reliable current control.

Key Features

? Dual H?Bridge for 2?phase Stepper Motors

? Programmable Peak?current up to 800 mA Using a 5?bit Current DAC

? On?chip Current Translator

? SPI Interface

? Speed and Load Angle Output

? Seven Step Modes from Full?step up to 32 Micro?steps

? Fully Integrated Current?sense

? PWM Current Control with Automatic Selection of Fast and Slow Decay

? Low EMC PWM with Selectable Voltage Slopes

? Active Fly?back Diodes

? Full Output Protection and Diagnosis

? Thermal Warning and Shutdown

? Compatible with 3.3 V Microcontrollers, 5 V Tolerant Inputs

? ?40°C to 125°C Temperature Range at 800 mA Peak Current