Pololu TB67S128FTG Stepper Motor Driver Carrier

• Pololu TB67S128FTG Stepper Motor Driver Carrier
• Offers protection against short-circuit and over-temperature
• Monitors the actual motor current
• Reduces automatically the drive current to min. power consumption
• Can interface directly with 3.3 and 5 V systems

The Pololu TB67S128FTG Stepper Motor Driver Carrier breakout board makes it easy to use Toshiba’s TB67S128FTG microstepping bipolar stepper motor driver, which features adjustable current limiting and microstepping down to 1/128-step.

In addition, it has the ability to dynamically select an optimal decay mode by monitoring the actual motor current, and it can automatically reduce the driving current below the full amount when the motor is lightly loaded to minimize power consumption and heat generation.

The driver has a wide operating voltage range of 6.5 to 44 V and can deliver approximately 2.1 A per phase continuously without a heat sink or forced air flow up to 5 A peak. It features built-in protection against under-voltage, over-current, and over-temperature conditions; the carrier board also adds reverse-voltage protection up to 40 V.

Stepper motors typically have a step size specification (e.g. 1.8° or 200 steps per revolution), which applies to full steps. A microstepping driver such as the TB67S128FTG allows higher resolutions by allowing intermediate step locations, which are achieved by energizing the coils with intermediate current levels.

The TB67S128FTG has a feature called Active Gain Control, or AGC, that automatically optimizes the motor current by sensing the load torque applied to the motor and dynamically reducing the current below the full amount.

This allows it to minimize power consumption and heat generation when the motor is lightly loaded, but if the driver senses an increased load, it will quickly ramp the current back up to the full amount to try to prevent a stall.