september 2009 doc id 15104 rev 1 1/40 AN2839 application note l6228 fully-integrated two- phase stepper motor driver introduction modern motion control applicati ons need more flexibility, whic h can only be addressed with specialized ic products. the l6228 is a fully-in tegrated stepper motor driver ic specifically developed to drive a wide range of two-phase (bipolar) stepper motors. this ic is a one- chip, cost-effective solution that includes several unique circuit design features. these features, including a decoding logic that can generate three different stepping sequences, allow the device to be used in many applicati ons, including microstepping. the principal aim of this development project was to produce an easy-to-use, fully-protected power ic. in addition, several key functions, such as pr otection circuitry and pwm current control, drastically reduce the number of external components to meet requirements for many different applications. the l6228 is a highly-integrated, mixed-signal power ic that allows the user to easily design a complete motor control system for two-phase bipolar stepper motors. figure 1 shows the l6228 block diagram. the ic integrates eight power dmos?s, a centralized logic circuit that implements the phase generation and a constant t off pwm current co ntrol technique (quasi-synchronous mode) for each of the two phases of the motor, plus other added features for safe operation and flexibility. figure 1. l6228 block diagram ! - v * $ 7 ( / 2 * , & 6 7 ( 3 3 , 1 * 6 ( 4 8 ( 1 & |