
Technical Articles
Stepper Motor Filters
PWM-driven motors, such as stepper motors are a major source of electromagnetic interference (EMI) in equipment. They also cause a number of problems in equipment, including damage to the motor’s bearings due to leakage current causing electrical discharge machining (EDM) and damage to motor’s insulation.
OnFILTER’s patented TF/TV-series filters stepper motor filters substantially reduce high-frequency leakage currents in motors and in wiring, assisting in compliance with the requirements of IEC61800-3, IEC60034-17/-25 and NEMA MG 1-2016, as well as with NAMUR recommendations. They also reduce interfering high-frequency noise within the tool resulting from operation of PWM-driven motors.
TF/TV series filters greatly reduce high-frequency currents on equipment ground, as well as overall EMI in the tool, lowering risk of EOS and reducing errors in automated equipment and testers.
-
No mechanical attachments
-
No changes in software
-
No adjustments
No Mechanical Fitting, No Wear, No Maintenance
OnFILTER' TF/TV series filters have no mechanical coupling to the motors - all connections are electrical. Their cost of ownership is zero.
Click on the model suitable for your motor/drive for details
Request a Quote
Basic Connection of Stepper Motor Filter
Reduction of Ground EMI Current with Stepper Motor Filters




Ground Current
Drive Pulse

No Filter

With Stepper Motor Filter
Ground Current
Drive Pulse
32 times or 30dB ground current suppression
Application Notes
Practical Aspects of Managing EMI-Caused EOS in IC Handlers and Similar Equipment
Measurements of Conducted Emission in the Manufacturing Environment
EMI-Generated EOS in a Wire Bonder
Mitigating EMI Issues in Servo Motors and Variable Frequency Drives
Dealing with EMI in Semiconductor Device Manufacturing
EOS Sources in Automated Equipment
EMI-Caused EOS Exposure of Components and its Mitigation
Origins of EOS in Manufacturing Environment and Its Classification