FAQ - Frequently Asked Questions - How to select a motor driver for a mechatronic system

Intro

Motor driver selection depends on motor type, voltage, current, control method, protection features, thermal design, EMC behaviour and mechanical load.

The driver must match both the motor and the real movement profile.

Key technical selection criteria

Evaluate:

  • motor type
  • supply voltage
  • continuous current
  • peak current
  • stall current
  • control interface
  • current sensing
  • braking requirements
  • protection features
  • thermal resistance
  • package
  • EMC behaviour

Motor types

Common motor types include:

  • brushed DC
  • BLDC
  • stepper
  • servo

Each type requires a different driver and control method.

Load profile

Check:

  • startup torque
  • acceleration
  • braking
  • duty cycle
  • stall conditions
  • speed range
  • mechanical load variation
  • operating temperature

Protection features

Useful protection includes:

  • overcurrent protection
  • overtemperature protection
  • undervoltage lockout
  • short-circuit protection
  • back-EMF handling
  • fault reporting

Common mistakes

  • selecting driver current too close to nominal motor current
  • ignoring stall current
  • insufficient thermal design
  • poor current sensing layout
  • no protection against inductive transients
  • underestimating EMC
  • not testing real mechanical load

Decision checklist

Before selecting a motor driver, define:

  • motor type
  • voltage range
  • peak current
  • stall current
  • control method
  • duty cycle
  • thermal limits
  • protection needs
  • EMC requirements
  • mechanical load profile

Need help selecting motor drivers or control components for a mechatronic system? Contact TOP-electronics.

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