AC servo drive
STOBER SD6 drive controller
High-performance servo drive controller with 2.3–85 A nominal and up to 153 A maximum current (4 kHz), EtherCAT, PROFINET or CANopen and optional SS1, SS2 and SLS safety.
Key specifications
| Feedback | EnDat 2.1/2.2, incremental, SSI; optional resolver, pulse/direction, sin/cos |
|---|---|
| Fieldbus | EtherCAT, PROFINET, CANopen |
| Continuous current (max) | 85 A |
| Peak current (max) | 153 A |
| Safe torque off | STO standard; optional SS1, SS2, SLS; SIL 3, PL e (Cat. 4) |
Summarised in our own words from STÖBER Antriebstechnik GmbH + Co. KG's published data; series maxima, individual models vary. Last checked 2026-10-30. Source 1
Specify Motion is not affiliated with STÖBER Antriebstechnik GmbH + Co. KG. STOBER and SD6 drive controller are used only to identify the product. Comparisons use published figures; always confirm against the current datasheet.
Typical applications
Alternatives that meet or exceed these figures
Engineers often come to us with a STOBER part number and leave with an alternative that is easier to source, quicker to deliver or a better fit for the machine. These 3 series from our supply network are the closest match on published figures.
Network-capable AMC digital drives spanning 10-747 VDC and 120-480 VAC, up to 150 A continuous and 250 A peak (27.4 kW peak power), in PCB, panel, machine and vehicle formats. They support almost any motor type and feedback, plus CANopen, EtherCAT, POWERLINK and Modbus.
| Published maximum | SD6 drive controller | DigiFlex Performance Servo Drives (DP,… |
|---|---|---|
| Continuous current | 85 A | 150 A meets or exceeds |
| Peak current | 153 A | 250 A meets or exceeds |
| Power | — | 27,400 W |
ADVANCED Motion Controls' ultra-compact, high power-density digital servo drives for 10-90 VDC systems, up to 100 A continuous and 200 A peak. They come in PCB, machine-embedded, panel and development-board formats, carry STO as standard, and run EtherCAT, CANopen or Ethernet/IP. Extended-environment models are rated -40 to +95 C.
| Published maximum | SD6 drive controller | FlexPro Digital Servo Drives (FE, FX, … |
|---|---|---|
| Continuous current | 85 A | 100 A meets or exceeds |
| Peak current | 153 A | 200 A meets or exceeds |
AMC's analogue servo drives for centralised control schemes: set up with DIP switches and potentiometers, commanded by +/-10 V or PWM. They span 10-400 VDC and 45-265 VAC, up to 150 A continuous and 250 A peak, in PCB, panel and vehicle formats. PCB extended-environment parts run -40 to +85 C.
| Published maximum | SD6 drive controller | AxCent Analogue Servo Drives (AB, AZ, … |
|---|---|---|
| Continuous current | 85 A | 150 A meets or exceeds |
| Peak current | 153 A | 250 A meets or exceeds |
Figures are the highest published for each series and are not always measured the same way. A higher figure is not automatically a better choice: mounting, duty cycle, feedback, connectors and approvals matter too. An engineer will check the fit against your application before recommending anything.
What an AC servo drive is
An AC servo drive, or servo amplifier, powers and controls a servo motor from mains supply. It rectifies the AC input to a DC bus, then uses an inverter of power transistors switched by PWM to produce controlled three-phase current in the motor. Nested current, velocity and position loops use encoder feedback to follow commands from pulse and direction, analogue or industrial Ethernet. Modern drives add auto-tuning, vibration suppression and safety functions such as safe torque off.
When engineers choose an AC servo drive
Choose an AC servo drive for mains-powered machines with servo axes from tens of watts to many kilowatts, such as packaging, machine tools and robotics. It gives precise, dynamic control with standard industrial interfaces. The trade-offs are cabinet space, wiring, EMC measures and the need to match motor and feedback. For low-voltage or mobile machines, a DC drive is more suitable; for many axes in one cabinet, a multi-axis drive may save space.
How to specify the STOBER SD6 drive controller
Send these with your enquiry and an engineer can confirm the right SD6 drive controller variant or an equivalent:
- Supply voltage and phases (V AC)
- Continuous and peak output current (A rms)
- Motor and feedback compatibility
- Command interface: pulse, analogue, EtherCAT, PROFINET and so on
- Safety functions, such as STO, and their rating (SIL, PL)
- Braking resistor and regenerative energy (W, J)
- Ambient temperature, mounting and cooling
Common mistakes to avoid
- Sizing on motor rated current without the drive's peak duration
- Ignoring regenerative energy on fast decelerations or vertical axes
- Leaving out EMC filtering and screened motor cables
- Mixing motor and encoder types the drive does not support
STOBER SD6 drive controller: frequently asked questions
What is the STOBER SD6 drive controller?
High-performance servo drive controller with 2.3–85 A nominal and up to 153 A maximum current (4 kHz), EtherCAT, PROFINET or CANopen and optional SS1, SS2 and SLS safety. Published series figures include continuous current 85 A, peak current 153 A. It is made by STÖBER Antriebstechnik GmbH + Co. KG; Specify Motion can help source it or propose an equivalent.
Who makes the STOBER SD6 drive controller?
The STOBER SD6 drive controller is made by STOBER (STÖBER Antriebstechnik GmbH + Co. KG) and is listed here for engineers comparing options. Specify Motion is not affiliated with STÖBER Antriebstechnik GmbH + Co. KG; brand names are used only to identify the product.
What is the continuous current of the STOBER SD6 drive controller?
The published series maximum continuous current is 85 A. Individual models and sizes in the SD6 drive controller range vary, so check the exact variant against your duty cycle, mounting and environment, or ask our engineers to confirm the right size for you.
Is there an alternative to the STOBER SD6 drive controller?
Yes. On published figures, ADVANCED Motion Controls DigiFlex Performance Servo Drives (DP, DZ, DV) and ADVANCED Motion Controls FlexPro Digital Servo Drives (FE, FX, FM, FD, FMP; Micro and Mini sizes) are the closest match from our supply network. An engineer confirms the fit against your application before recommending anything.
Does a servo drive need a braking resistor?
When a servo motor decelerates, it acts as a generator and returns energy to the drive's DC bus. If the bus capacitors cannot absorb it, the voltage rises and the drive trips. A braking resistor dissipates the energy as heat. Fast decelerations, high inertia and vertical axes usually need one.
What is safe torque off on a servo drive?
Safe torque off, or STO, is a safety function that removes power that could produce torque at the motor, without disconnecting the drive supply. It is defined in IEC 61800-5-2 and used as part of a machine's safety system. Check the safety level achieved and wiring requirements.
Further reading: How to select a servo drive · How to select a servo motor · Servo drives
Other ac servo drive series
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