Microstepping motor driver with sensorless stall detection
( 01 Dec 2003 )
Trinamic Microchips GmbH has introduced a microstepping motor driver that features a sensorless load measurement function, which detects motor stalling and mechanical overload conditions before a step-loss occurs.
The TMC246 is said to be a cost-effective and reliable high-performance component that enables customers to detect stall conditions, thereby eliminating the need for external optical encoders or reference switches. The chip is designed as a universal smart power driver IC for use in all applications where stepping motors are deployed. Application areas include IT peripherals, automotive actuators, industrial automation, vending and gaming machines, ATMs, medical devices and lab automation.
The TMC246's load-detection feature is said to work reliably with any stepper motor without the need for the extensive parametrization required by conventional methods based on complex signal processing. Another differentiating factor of the TMC246 is that the integrated robust load-detection circuit is independent from the supply voltage. The load status of the motor is transmitted via the digital interface of the driver IC, enabling convenient processing of this information.
Integrated on the TMC246 are two full bridges that achieve an on-resistance (RDSON) of 0.2˝ per switch at 25ˇC. The low RDSON eliminates the need for dedicated heat sinks and aluminum housings, and allow the use of cost-effective simple housings. The resulting lower packaging cost and smaller footprint allow for smaller electronic control unit (ECU) designs.
