PCB-mount drive
Synapticon SOMANET Circulo PCB-mount drive
Ring-shaped servo drives (Circulo 7 and 9) that sit inside a robot joint around the hollow shaft, up to 60 V and 60 A rms, with up to two integrated 20-bit absolute encoders, EtherCAT at up to 4 kHz and more than ten SIL3 / PL e safety functions.
Key specifications
| Voltage (max) | 60 V |
|---|---|
| Outer diameter (max) | 92 mm |
| Data / bus | EtherCAT, FSoE |
| Feedback | up to two integrated absolute encoders, optional battery-backed multi-turn |
| Fieldbus | EtherCAT (CiA 402), up to 4 kHz |
| Current (max) | 60 A |
| Resolution (max) | 20 bit |
| Sizes | Circulo 7 (72 mm), Circulo 9 (92 mm) |
| Safety | STO, SBC, SS1, SS2, SLS and more; SIL3 / PL e |
Summarised in our own words from Synapticon GmbH's published data; series maxima, individual models vary. Last checked 2026-10-30. Source 1
Notes on this data
Page inconsistent on whether 72/92 mm are diameters or radii; drawings label inner radii 20 and 40 mm. Current is RMS; continuous vs peak not separated.
Specify Motion is not affiliated with Synapticon GmbH. Synapticon and SOMANET Circulo 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 Synapticon 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.
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 | SOMANET Circulo | FlexPro Digital Servo Drives (FE, FX, … |
|---|---|---|
| Continuous current | 60 A | 100 A meets or exceeds |
| Peak current | — | 200 A |
Single-axis 24-70 VDC servo drives from 5 to 60 Arms (180 A peak), in RS (Modbus/pulse/analogue) and CAN (CANopen/analogue) versions. They drive brushless, brushed and PMSM motors including ELVM, with STO SIL3 and backup logic supply on the 40/60 A models.
| Published maximum | SOMANET Circulo | ELD2 Series Low-Voltage DC Servo Drives |
|---|---|---|
| Continuous current | 60 A | 60 A meets or exceeds |
| Peak current | — | 180 A |
| Power | — | 2,500 W |
| Axes | — | 1 |
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 | SOMANET Circulo | DigiFlex Performance Servo Drives (DP,… |
|---|---|---|
| Continuous current | 60 A | 150 A meets or exceeds |
| Peak current | — | 250 A |
| Power | — | 27,400 W |
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 a PCB-mount drive is
A PCB-mount servo drive is a compact servo drive module designed to be soldered or plugged into a host circuit board, rather than mounted in a cabinet. It contains the power stage and control loops for brushless, brushed or stepper-style motors, with interfaces such as CANopen, EtherCAT, SPI or analogue. Some versions are supplied with evaluation or carrier boards. Very high power density lets them fit inside robots, medical devices and instruments.
When engineers choose a PCB-mount drive
Choose a PCB-mount drive when the motor control must be embedded in the product, such as surgical robots, exoskeletons, AGVs, drones and laboratory instruments. It saves space and weight and integrates with the host board. The trade-offs are design responsibility and thermal management: the host board must provide heatsinking, connectors, EMC and protection. For machines with space for cabinets, packaged drives are simpler.
How to specify the Synapticon SOMANET Circulo
Send these with your enquiry and an engineer can confirm the right SOMANET Circulo variant or an equivalent:
- Supply voltage (V DC)
- Continuous and peak current (A)
- Motor and feedback type
- Interface: CANopen, EtherCAT, SPI or analogue
- Size and mounting (mm)
- Thermal path and heatsinking
- Safety functions and approvals
Common mistakes to avoid
- Ignoring the thermal path on the host board
- Not designing EMC filtering and protection
- Assuming evaluation board performance in a sealed product
- Leaving out testing for safety and medical approvals
Synapticon SOMANET Circulo: frequently asked questions
What is the Synapticon SOMANET Circulo?
Ring-shaped servo drives (Circulo 7 and 9) that sit inside a robot joint around the hollow shaft, up to 60 V and 60 A rms, with up to two integrated 20-bit absolute encoders, EtherCAT at up to 4 kHz and more than ten SIL3 / PL e safety functions. Published series figures include voltage 60 V, outer diameter 92 mm, current 60 A, resolution 20 bit. It is made by Synapticon GmbH; Specify Motion can help source it or propose an equivalent.
Who makes the Synapticon SOMANET Circulo?
The Synapticon SOMANET Circulo is made by Synapticon (Synapticon GmbH) and is listed here for engineers comparing options. Specify Motion is not affiliated with Synapticon GmbH; brand names are used only to identify the product.
What is the voltage of the Synapticon SOMANET Circulo?
The published series maximum voltage is 60 V. Individual models and sizes in the SOMANET Circulo 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 Synapticon SOMANET Circulo?
Yes. On published figures, ADVANCED Motion Controls FlexPro Digital Servo Drives (FE, FX, FM, FD, FMP; Micro and Mini sizes) and Leadshine ELD2 Series Low-Voltage DC Servo Drives are the closest match from our supply network. An engineer confirms the fit against your application before recommending anything.
What is the benefit of a PCB-mount servo drive?
A PCB-mount drive puts motor control inside the product, saving space, weight and cabling. It integrates with the host electronics and can be very power-dense. The host board designer takes on thermal, EMC and protection design, so evaluation boards are often used first.
How is heat removed from a PCB-mount drive?
Heat is usually conducted through the drive's base or pins into the host board and a heatsink or chassis. Copper area, thermal interface materials and airflow all matter. Continuous current ratings often assume specific heatsinking, so check the conditions in the datasheet.
Further reading: How to select a pcb mount servo drive · How to select a servo drive · Servo drives
Other pcb-mount drive series
Spec builder
Specify what you need instead of SOMANET Circulo
Select every part you need, answer the questions an applications engineer would ask, and see your summary before we ask for any details.
- 1Products
- 2Performance
- 3Environment
- 4Volumes
- 5Your spec
Engineer support
Let our experienced engineers do the hard work for you
Tell us how you use the Synapticon SOMANET Circulo: the load, speed, duty and environment. Our engineers will confirm whether it is still the right part, find it for you, or propose an alternative that fits better.
- Reviewed by an engineer, not an autoresponder
- Like-for-like and better-fit alternatives
- Standard, modified and custom options
Prefer to configure it? Use the spec builder.