6
Source-backed boundaries
6 primary references cover drive safety, current definitions, current sensing, and I²t protection; each is bounded to its stated design or vendor.
Hybrid Tool & Engineering Report
10A Compact Servo Drive
OEMs can screen current, pulse, and cooling.
10A Servo Drive Sizing Calculator
Motor-phase RMS; convert Apeak/DC-bus. Examples; 10A is a page reference.
Ready to Screen a 10A Drive
Review the units, enter the duty-cycle values, and run the sizing screen.The first result will show candidate, boundary, outside-reference, or low-utilization guidance.Next step: Fill all fields, then calculate. A candidate result still needs supplier confirmation.
Continuous utilizationAwaiting input
Enter Arms continuous current
Peak utilizationAwaiting input
Enter Arms peak current and pulse duration
Peak-pulse duration screenAwaiting input
Enter peak current and pulse duration
Assumptions shown in result
- - Enter motor phase RMS current; convert peak-amplitude or DC-bus values first.
- - Use the cooling mode that matches the real mounting condition.
- - Treat every output as a screen until supplier ratings are confirmed.
Published July 19, 2026; evidence and assumptions reviewed October 11, 2026. Screening only: confirm ratings and thermal fit with the supplier.
4
Scenario screens
Examples show 4 candidate, boundary, low-utilization, and above-reference outcomes using the same calculator rules.
5
Supplier checks
The RFQ list contains 5 checks for current, pulse, cooling, motor control, and regeneration evidence.
Decision Summary
Key Takeaways for 10A Drive Selection
4x
Thermal load
For the same motor winding resistance, increasing phase current from 5A to 10A produces 4x winding copper loss (I²R). The real temperature rise still depends on duty cycle, construction, and the thermal path.
Peak vs Cont.
Rating ambiguity
A 10A label is incomplete without its current basis. Ask whether it means continuous RMS, peak amplitude, or another definition, and request pulse duration, I²t limits, and cooling conditions.
Not magic
GaN boundary
TI’s TIDA-00909 is one 48V GaN inverter example tested up to 100kHz PWM. That result is design-specific; switching frequency still needs thermal, layout, and EMI validation.
How the Tool Decides
The 10A value is a comparison reference in Arms for this screen, not a universal product rating. Convert supplier values stated as Apeak or DC-bus current first; pulse limits also depend on I2t, cooling, and repetition rate.
| Input | Why it matters | Screening rule |
|---|---|---|
| Continuous current | Sets average heat load in FETs, copper, connectors, and enclosure surfaces. | Compare Arms with the 10A page reference; the cooling mode adds a review trigger, not a verified product limit. |
| Pulse current | Checks the timed operating point against the same RMS reference after converting any peak-amplitude or DC-bus data. | Above 10 Arms is outside this page reference; a supplier exception needs a documented rating curve. |
| Peak duration | Separates a fast torque impulse from a thermal event that behaves like continuous load. | Longer pulses require a vendor I2t curve, ambient temperature, and repetition rate. |
| Cooling condition | The same PCB can be safe on a chassis plate and unsafe inside a sealed joint. | Sealed: 4 Arms / 1 s; conduction: 8 Arms / 2 s; active: 10 Arms / 4 s. These page-specific triggers are not vendor ratings. |
These thresholds are page-specific triage rules, not limits derived from a particular drive datasheet, standard, or thermal test. A candidate result only means the inputs stay below these review triggers; confirm the selected drive’s I²t curve and thermal performance in the target assembly.
Evidence Layer
Sources, Scope, and Known Limits
The page separates general engineering rules from vendor-specific ratings. The linked examples show why RMS and peak values differ; supplier documentation must still confirm the selected model’s current basis, cooling conditions, and pulse limits.
Review cycle: refreshed every six months, or sooner when supplier ratings, safety standards, or GaN motor-drive guidance change.
| Source | Supports | Boundary | Date note |
|---|---|---|---|
| IEC 61800-5-1 adjustable speed electrical power drive safety standard | Electrical, thermal, and energy safety must be reviewed for power drive systems, not only motion performance. | Use the standard to frame safety review; it does not publish your vendor-specific current rating. | IEC source reviewed October 11, 2026 |
| TI TIDA-00909 48V/10A GaN inverter reference design | The design specifies 7 Arms / 10 A peak output and reports testing up to 100 kHz PWM, showing why current definitions and test conditions must be stated. | This is one reference design, not a universal current rating, thermal result, or switching-frequency target. | TI reference reviewed October 11, 2026 |
| TI High Resolution, Small Form Factor Phase Current Sense for 48V Robotics and Servo Drives | TI identifies accuracy, effective resolution, latency, common-mode transient immunity, and EMI as current-sense subsystem design constraints. | This application note describes one 24V–60V shunt-based sensing design; its requirements are not universal specifications for every motor drive. | TI application note reviewed October 11, 2026 |
| Synapticon drive documentation for I2t protection | I²t protection is vendor-configured overload protection; its threshold and recovery behavior must be checked for the exact drive. | I2t parameters are set by each drive vendor and firmware configuration; request the actual curve before procurement. | Vendor documentation reviewed October 11, 2026 |
| Elmo Gold Twitter servo drive current-rating table | The 10/100 configuration lists a 10A amplitude continuous value, a 7.1A sinusoidal RMS limit, and a peak limit stated separately. | Ratings vary by model and supply voltage; use the exact configuration and its test conditions. | Supplier product data reviewed October 11, 2026 |
| TI Precision ADCs in Servo Drives | Servo-drive ADC selection spans different resolution and sampling-rate options; bit depth alone does not guarantee current-control accuracy. | This document covers a range of servo-drive signal chains; device selection depends on the actual bandwidth and noise requirements. | TI application brief reviewed October 11, 2026 |
| Public example | Current rating | Decision use |
|---|---|---|
| Elmo Gold Twitter 10/100 configuration | 10A sinusoidal/DC amplitude continuous; 7.1 Arms sinusoidal continuous RMS; peak limit stated as 2 × Ic | Shows why the exact model and current basis belong in an RFQ; this is a product-family rating, not a universal 10A rule. |
| TI TIDA-00909 GaN inverter reference design | 7 Arms / 10 A peak output; tested up to 100 kHz PWM | Reference design only; its tested values illustrate why RMS and peak figures must not be compared without conversion. |
If your result is a boundary case, package the duty cycle, cooling path, ambient temperature, and motor data before asking for a written supplier rating.
Send assumptionsTrade-Off Analysis
Lower-Current vs 10A Compact Servo Drive Decision Points
Oversizing to 10A can be correct for torque bursts, but it also changes the power path, sensing range, regeneration strategy, and mechanical package.
| Parameter | Lower-current option | 10A class | Decision impact |
|---|---|---|---|
| Power path | Lower copper and connector burden | High-current PCB, busbar, or bonded thermal path | A 10A design may need heavier copper, busbars, or parallel FET paths; verify manufacturable trace width and temperature rise. |
| Connector and cabling | Easier routing inside compact joints | Larger contacts and lower-resistance harnessing | Oversizing can make the joint harder to package even when the motor torque looks attractive on paper. |
| DC bus energy | Lower braking energy and ripple stress | Higher bus capacitance and braking path review | Regeneration can trip the DC bus before current capability becomes the limiting factor. |
| Current sensing | Potentially better resolution when the sensor range matches the load | 10A reference range; verify performance at the real operating current | A current-sense range much wider than the operating current can reduce usable resolution; confirm the actual sensor range, noise, ADC performance, and sampling window. |
| Procurement cost | Lower BOM and simpler qualification | Higher drive, thermal, cable, and test cost | Use the smaller class when 10A is only a vague safety margin, not a measured duty-cycle requirement. |
Result Boundaries and Required Next Actions
| Tool result | Typical condition | Required action |
|---|---|---|
| Candidate fit | Continuous current stays below the selected cooling review trigger; peak is below 9A and any 7A+ pulse stays within its duration trigger. | Proceed to supplier quotation with explicit current and cooling clauses. |
| Boundary case | Continuous current exceeds its cooling review trigger, peak is at least 9A, or a 7A+ pulse exceeds its duration trigger. | Request thermal simulation, I2t curve, duty cycle review, and mounting details. |
| Outside envelope | Continuous or pulse current exceeds the 10 Arms page reference. | Move to a larger drive class or reduce the torque requirement. |
| Likely oversized | Continuous current is at or below 1A and pulse current is at or below 2A (20% of the page reference). | Compare a lower-current drive and check its sensing range and control performance. |
Risk Map
The highest-impact mistakes are usually not the headline current rating. They are thermal assumptions, regeneration handling, sensing range, and switching/layout validation.
| Risk | Trigger | Mitigation |
|---|---|---|
| Thermal shutdown or unsafe surface temperature | Sustained high current in a sealed joint relying entirely on conduction | Specify the complete thermal stack (substrate, interface material, baseplate or chassis), ambient temperature, duty cycle, and I2t limits in the RFQ. |
| Low-current torque noise | The current-sense full scale is much wider than the joint’s normal holding current | Ask for current-sensor range, noise, ADC performance, and sampling timing at the actual holding current; validate torque ripple on the target motor. |
| Regeneration over-voltage | High deceleration current pushes energy back to the DC bus | Review battery absorption, braking resistor sizing, and over-voltage trip thresholds. |
| EMI or switching instability | A high PWM frequency is chosen without checking switching loss, layout parasitics, and EMI on the target design | Validate conducted/radiated emissions, layout parasitics, and low-inductance power loops before freezing the PCB. |
Procurement Check
Questions to Ask Before Buying a 10A Drive
| Question | Why it matters |
|---|---|
| What is the continuous current rating? | Establishes whether 10A means continuous output or a short-time peak, and which current basis the supplier uses. |
| What pulse current is allowed, for how many seconds, and at what repetition rate? | Prevents the common error of treating a one-time pulse rating as a robot duty-cycle rating. |
| What cooling surface, ambient temperature, and enclosure assumptions were used? | Makes the thermal number reproducible in the actual robot joint. |
| What motor inductance, PWM frequency, and current-loop bandwidth are supported? | Confirms the drive can control the compact joint motor cleanly, not just survive the current. |
| How is regenerative energy handled? | High-current braking can fail through DC bus over-voltage even when torque output is adequate. |
Scenario Checks
Example Outcomes From the Calculator Logic
These inputs are illustrative screening examples, not measured motor loads or supplier product ratings.
| Case | Input assumption | Outcome |
|---|---|---|
| Humanoid knee jump recovery | 3.5 Arms continuous, 8 Arms pulse, 0.5s, conduction to chassis | Candidate fit for a supplier shortlist; confirm the continuous and pulse ratings and repetition rate. |
| AGV steering actuator | 4 Arms continuous, 9.5 Arms pulse, 2s, sealed enclosure | Boundary case; request the exact pulse curve and thermal validation for the sealed mounting. |
| Low-torque robot joint | 0.8 Arms continuous, 1.5 Arms pulse, 0.2s, active cooling | Potentially oversized by the page utilization heuristic; compare lower-current options and sensor performance. |
| High-load actuator | 8 Arms continuous, 12 Arms pulse, 0.2s, active cooling | Above the 10 Arms reference; compare a higher-rated drive and its documented current limits. |
Frequently Asked Questions
Do I really need a 10A compact servo drive?
Compare its rated current with the measured duty cycle on the same RMS or peak basis. If the continuous requirement is at or below 1 Arms and pulse requirement at or below 2 Arms, this page flags low utilization; a smaller option may be worth evaluating.
Why can a value below 10A still be a boundary case?
The 10A figure is only a page reference. This screen uses a cooling-specific review trigger for continuous current and flags pulses close to the reference; neither value is a supplier rating.
What proof should a supplier provide for continuous current?
Ask for the exact part number, continuous current, peak current, pulse duration, repetition rate, ambient temperature, cooling surface, and whether the current is RMS phase current or another definition.
Can I use a 10A compact drive inside a sealed joint?
Possibly, but the result depends on the drive loss, mounting interface, enclosure, ambient temperature, and duty cycle. Use the sealed mode only as a page screening prompt; require the supplier’s derating data and a thermal test in the target assembly.
Does EtherCAT or CANopen change the sizing result?
The protocol does not change the current envelope, but it affects integration risk. Check supported feedback, synchronization, safety functions, diagnostics, and current-loop update behavior alongside the thermal rating.
What is the difference between peak and continuous current?
Continuous current is the manufacturer’s stated current under defined steady-state conditions; peak current is a short-duration limit with separate conditions. The units can differ too: for example, TI’s TIDA-00909 lists 7 Arms and 10 A peak, so convert before comparing.
Does GaN automatically make 10A safe in a small joint?
No. GaN can reduce switching loss and support compact high-frequency designs, but the drive still needs validated thermal paths, low-inductance layout, sensing accuracy, DC bus energy handling, and EMI control.
Can I exceed 10A for less than one second?
Treat a value above this page’s 10 Arms reference as outside the screen. A supplier may allow a higher pulse, but ask for a written curve with current basis, duration, repetition rate, ambient temperature, and cooling condition.
Can an oversized drive make low-current control worse?
It can. If the current-sense range is much wider than the holding current, the usable resolution may fall; check the sensor noise, ADC performance, and control behavior at the actual operating point.
Which current unit should I enter?
Enter motor-phase RMS values for both continuous and pulse operation. Convert peak-amplitude or DC-bus values to the same basis first; never compare those definitions directly.
What should I request from a supplier?
Ask for the continuous rating, pulse-current duration, I2t curve, cooling condition, supported motor inductance, current-loop bandwidth, and regeneration handling in one written specification.
Is the calculator enough for final design release?
The calculator is a screening tool. Final selection still requires vendor derating data, thermal testing, safety review, and validation on the target motor and mechanical package.
Next Steps
- Browse GaN Servo Drives to compare compact drive families after your current envelope is known.
- If you plan to design the PCB into your own housing, check the 10A board level servo drive integration guide.
- Start with the GaN low-voltage servo drive family when compact 24V to 60V robotics packaging is the main constraint.
- Compare the 48V servo driver board path if the actuator architecture is centered on a bare-board integration.
- Use the GaN servo drive selection guide to turn the calculator output into a full drive shortlist.
- Review humanoid robot joint requirements when the 10A request comes from compact knee, hip, or shoulder actuators.
Inquiry Email
Include voltage, current, motor, encoder, protocol, board envelope, and quantity stage.