Controller IC Executes Stepper Commands In Real-Time Sans PC

Combined with a minimum number of external parts, the SMC-25 embedded controller IC provides a solution for operating stepper motors. The built-in UART provides access to a 30-plus command set, six general-purpose ports, and 2 kbytes of non-volatile memory. Commands can be executed in real-time or stored for execution without using a host computer. Auxiliary step pulse and directional inputs allow motion generation via external pulse sources, with limit switch protection and position counter tracking. Selectable phase sequences or a user-programmed table can produce 1-, 2-, 3-, or 4-phase outputs. For evaluation and board-level solutions, a complete, 2A unipolar drive/indexer is available for less than $100. The 5V motor controller chip comes in 44-pin PLCCs, but is also available in other packages.