This part is a kind of semiconductor called TMC249A.

Function of this product has High current microstep stepper motor driver.

Manufacturers : TRINAMIC

Image and pinout :

Some of the text within the PDF file :

TMC249 / TMC249A DATA SHEET (V2.10 / 2011-Aug-10) 1 TMC249/A – DATASHEET High current microstep stepper motor driver with stallGuard™, protection / diagnostics and SPI Interface TRINAMIC Motion Control GmbH & Co KG Hamburg, Germany ® www.trinamic.com Features The TMC249 / TMC249A (1) is a dual full bridge driver IC for bipolar stepper motor control applications. The TMC249 is realized in a HVCMOS technology and directly drives eight external LowRDS-ON high efficiency MOSFETs. It supports more than 6000mA coil current. The low power dissipation makes the TMC249 an optimum choice for drives, where a high reliability is desired. With additional drivers, motor current and voltage can be increased. The integrated unique sensorless stall detection (pat. pend.) stallGuard™ makes it a [ ... ]

TMC249A PDF Datasheet Download