AC servo drives · Continuous and peak current against the motor, supply voltage, control loop cycle times, feedback interfaces, fieldbus and safe torque off
A servo drive powers a servo motor and closes the current, speed and position loops using feedback from the motor's encoder or resolver, following commands from a motion controller or PLC. Settle three things before comparing drives: the continuous and peak current the motor and duty cycle need, the supply voltage and phases at the machine, and the feedback type, fieldbus and safety functions the control system expects.
AC servo drives (amplifiers) for synchronous servo motors in single- and multi-axis machines, including drives integrated into motors. Servo motors themselves, stepper drivers, variable-frequency drives for induction motors, spindle inverters and motion controllers are outside this page; servo motors, stepper drivers and VFDs have their own pages.
01
Beckhoff lists its AX1000 economy servo drives in two versions: a single-phase 1 × 110–240 V AC supply for the low power range from 1.65 to 6.9 A, and a three-phase 3 × 208–480 V AC supply for the higher range from 3.4 to 12 A, each in single- and dual-axis form. Its AX5000 compact servo drives are available up to an output of 118 kW and connect to mains from 100 to 480 V AC with an integrated mains filter. [2] [1]
A linked supplier lists its F01N servo drives from 400 W single-phase 220 V to 7.5 kW three-phase 380 V, and gives one 5.0 kW model (F01N-017B) at 16.5 A rms continuous and 42 A rms maximum output current on a three-phase 380–440 V supply, with a built-in braking resistor. [3]
Editorial calculation: 42 ÷ 16.5 ≈ 2.5, so that drive can deliver about two and a half times its continuous current for short acceleration peaks. Size the drive so the motor's RMS current over the duty cycle stays below the continuous rating and the highest acceleration current stays below the peak rating, for the same supply voltage.
Editorial note: drives and motors are rated as matched pairs. Check that the drive's continuous and peak current cover the motor's rated and peak current, and that braking energy from decelerating loads can be absorbed by the built-in or an external resistor.
Give the supplier the motor model or its rated and peak current, voltage and feedback type; the supply voltage and phases; the duty cycle or move profile; the control mode (position, speed, torque) and command interface (pulse, analogue, fieldbus); the safety function required; braking energy; enclosure temperature; and the number of axes.
02
Beckhoff says the AX5000 achieves a current control cycle of up to 62.5 µs for highly dynamic positioning, communicates over EtherCAT, and has a feedback interface that supports resolvers and high-resolution encoders with EnDat, BiSS or Hiperface, with fully digital EnDat 2.2 or BiSS-C via an option card. It supports asynchronous, linear, torque and voice-coil motors as well as its own synchronous servomotors, and offers TwinSAFE safety functions including STO and SS1. [1]
On its servo drive range page Beckhoff adds that a multi-feedback interface lets third-party motors be operated with EnDat 2.2, BiSS-C, TTL or SinCos 1 Vss feedback. [2] A linked supplier says modern servo drives integrate with protocols such as RS485, EtherCAT and PROFINET, and that servo systems maintain torque across a wide speed range whereas stepper motors tend to lose torque at higher speeds. [4]
Another linked supplier describes a servo drive as an electronic amplifier that monitors the feedback signal and continually corrects deviation, and distinguishes it from a motion controller, which plans the motion the drive executes. [5]
Editorial note: feedback compatibility decides whether a drive can run a given motor. List the motor's encoder protocol and resolution in the request, not only its power.
03
Suppliers linked to this page list AC servo drives; each card links to the page reviewed.
The listings reviewed range from pulse-command and EtherCAT servo drives with matched motors to spindle servo drives for machine tools; ask each for continuous and peak current per model, supported encoder protocols, fieldbus and STO certification.
04
This is a functional reference built from the sources cited; it is not one maker's specification.
| Part | Role | Fix in the order |
|---|---|---|
| Mains input and filter | Supply voltage and phases. [1] [2] | Voltage; phases. |
| Power stage | Continuous and peak current. [2] [3] | Current ratings. |
| Control loops | Current, speed, position cycles. [1] | Cycle time; modes. |
| Feedback interface | Resolver, EnDat, BiSS, Hiperface. [1] [2] | Protocol. |
| Communication | EtherCAT, PROFINET, RS485, pulse. [1] [4] | Interface. |
| Braking and safety | Braking resistor; STO/SS1. [3] [1] | Resistor; safety level. |
05
A servo drive quotation needs values for your axes. The table explains each field, gives published values where a reviewed source states them, and says what to obtain from the supplier.
| Field | What it means and published values | Ask the supplier for |
|---|---|---|
| Rated Power (kW) | Ranges to 118 kW (AX5000); 0.4–7.5 kW (F01N). [2] [3] | Power per model. |
| Rated Current (A) | 1.65–12 A (AX1000); 16.5 A rms (5 kW F01N). [2] [3] | Continuous current. |
| Peak Current (A) | 42 A rms on the 5 kW F01N. [3] | Peak and duration. |
| Supply Voltage (V AC) | 1 × 110–240 or 3 × 208–480 V AC. [2] | Voltage; phases. |
| Control Voltage (V DC) | Logic supply. | Voltage. |
| Frequency Response (kHz) | Current control cycle 62.5 µs. [1] | Loop bandwidth. |
| Speed Range | Motor speed range. | Range. |
| Position Accuracy (mm) | Set by feedback and mechanics. [1] | Encoder resolution. |
| Speed Accuracy (%) | Speed loop. | Value. |
| Operating Temperature (°C) | Cabinet ambient. | Range; derating. |
| Storage Temperature (°C) | Non-operating. | Range. |
| Protection Rating | Cabinet or machine-mounted. [2] | IP rating. |
| Weight (kg) | Per drive. | Weight. |
06
Paste it into your enquiry below or into an email to a maker, then replace every bracket.
Motor: [model; rated and peak current; feedback] Supply: [voltage; phases] Duty: [move profile; RMS and peak] Control: [position; speed; torque; command interface] Network: [EtherCAT; PROFINET; pulse; analogue] Safety: [STO; SS1; level] Braking: [energy; resistor] Axes: [number; single or multi-axis]
These companies list servo drives.
Lists F01N servo drives from 400 W single-phase 220 V to 7.5 kW three-phase 380 V, with current ratings per model.
Product scope checked 2026-10-11
Lists servo drives matched to its servo motors and linear modules.
Product scope checked 2026-10-11
Lists servo drives and motors, including pulse-command models.
Product scope checked 2026-10-11
Lists S6 spindle servo drives of 2.2–11 kW with Modbus or EtherCAT and dual encoder interfaces.
Product scope checked 2026-10-11
Lists an ACSMX series servo drive among its AC drives.
Product scope checked 2026-10-11
Explore company information and manufacturing capabilities, then discuss the scope of your project with a relevant supplier.
Beckhoff lists AX1000 drives from 1.65 to 6.9 A single-phase and 3.4 to 12 A three-phase. [2]
Beckhoff gives a current control cycle of up to 62.5 µs for its AX5000. [1]
Beckhoff's AX5000 supports resolvers and encoders with EnDat, BiSS or Hiperface. [1]
One linked supplier lists a 5 kW drive at 16.5 A rms continuous and 42 A rms maximum. [3]
Sources checked 2026-10-11. Beckhoff is a servo drive maker publishing current, supply, control-cycle, feedback and safety data; Finger, LIMON and STEP are linked suppliers publishing ratings and descriptions.
Ask for use case, specification boundaries, supplier type, and RFQ preparation information for this product.
Compare manufacturer profiles with relevant product and process capability.