StallGuard technology available in TMC246 and TMC249 driver chips for bipolarstepmotor control is capable of sensorless stall detection without the need for an encoder.
The TMC246 is a dual full-bridge driver IC. It can operate at high temperatures of up to 105°C or at high currents of up to 1.5 A/phase. Its low current consumption and high efficiency together with internal DACs allow for microstepping as well as smart current control that permits cool motor and driver operation. The device can be controlled via serial interface or via analog/ digital input signals. Short-circuit, temperature, undervoltage and overvoltage protection are all integrated. The TMC249 is the highcurrent version of the TMC246 and can support up to 75 Vdc/10 A. This drive chip can also be used for unipolar stepmotors. Only four external PMOS transistors are required for unipolar operation. StallGuard sensorless stall detection lets the chips work in applications where a reference point is needed, but where a switch cannot be used.
Lin Engineering, 1990 Russell Ave., Santa Clara, CA 95054, (408) 919-0200, linengineering.com
