Basics of PCD Series: Pulse Control LSIs

This document is intended for customers who will use our LSIs specifically to control motors for the first time. It explains operations in terms of the simplest NPM LSIs, the "PCD series." A PCD divides a string of reference clock pulses and creates a variety of pulse strings at different frequencies that are appropriate for controlling specific motors. By sending operating patterns and commands from a CPU, you can leave the control of a motor up to the PCD. This decreases the overhead imposed on the CPU. This PCD series provides most of the functions required to control stepper motors. It also has an excitation sequence output function used with 2-phase stepper motors. You can select a suitable model for the number of axes you need to control (1 axis: PCD4500, PCD4511, 2 axes: PCD4521, 4 axes: PCD4541). Reference clock - This is the basic frequency used when operating the PCD. Similar to CPUs, LSI operation is also based on a reference clock. CPUs used in general equipment do not need to be as fast as the CPUs in personal computers. (Lower speeds are fast enough.)