Interactive tool + OEM report
24V GaN Servo Control Board
Estimate switch temperature from device loss and matched thermal data.
Request an OEM engineering reviewPublished · Evidence reviewed · By GaN Servo
Decision summary
A 24V GaN servo control board should be evaluated from its actual device losses, thermal path, motor waveform, and transient conditions. A bus-voltage label or board footprint alone cannot establish a safe continuous-current rating.
Start with device data
Estimate or measure loss in the hottest switch at the intended voltage, current, modulation, and switching conditions.
Match the thermal path
Junction temperature depends on the real device-to-ambient path, including PCB copper, enclosure, airflow, and nearby heat.
Validate the assembly
Use the estimate to prepare a prototype test plan, then confirm thermal margin and protection behavior on the target motor.
Evidence and scope
Evidence reviewed October 11, 2026. The public TI references below support general loss and validation methods. They do not publish measured performance for this specific 24V GanServo board, so this page makes no board-specific efficiency, current, temperature, or acoustic-performance claim.
| Primary source | What it supports | Scope limit |
|---|---|---|
| TI LMG5200 datasheet | Separates conduction, switching, and driver loss and ties thermal performance to device and PCB layout. | The LMG5200 is a specific 80V, 10A half-bridge; its values do not characterize this board. |
| TI switching-loss brief | Explains switching overlap and the difference between silicon body-diode recovery and GaN third-quadrant conduction. | General explanation; it does not provide a universal loss reduction or dead-time setting. |
| TI 250W motor-inverter reference design | Provides a documented three-phase GaN motor-inverter design and design guide. | It is a different 250W design and does not validate a 24V servo board or a production assembly. |
The references are manufacturer documents. Use the selected device’s current datasheet and application guidance for a real design review.
How the thermal check works
For a first-order steady-state check, the calculator applies the entered hottest-device loss to the entered junction-to-ambient thermal resistance, then adds the local ambient temperature.
Included
Average loss for the hottest switch, a matching steady-state thermal resistance, and the local ambient temperature.
Not included
Switching transients, adjacent-device heating, parameter tolerance, changing airflow, motor behavior, and project-specific design margin.
Design trade-offs to resolve
| Decision area | What changes the result | Evidence to compare |
|---|---|---|
| GaN vs. silicon stage | Device resistance at operating temperature, switching energy, driver loss, dead-time, and the control waveform. | Loss breakdown using selected parts at matched bus, current, frequency, and cooling conditions. |
| Switching speed and EMI | Gate-drive strength, commutation-loop parasitics, cable and motor characteristics, and filtering. | Switch-node waveforms, conducted/radiated pre-compliance results, and motor-side measurements. |
| Regeneration and bus protection | Inertia, supply absorption, braking strategy, wiring, and clamp/protection thresholds. | Worst-case bus-voltage capture during acceleration, deceleration, and fault handling. |
| Thermal packaging | Device placement, copper spreading, vias, enclosure contact, airflow, and neighboring heat sources. | Board-specific thermal model and stabilized prototype measurements at worst-case ambient and load. |
Do not choose from a headline current or efficiency number alone. Ask for the test conditions and compare the complete assembly, including protection, filtering, cooling, and test coverage.
Need an engineering review for your operating point?
Share the bus range, motor and encoder data, estimated device loss, assembly thermal path, and test requirements so the team can review the assumptions for a custom board program.
Request an OEM engineering reviewPrototype and manufacturing evidence to request
Treat these as RFQ acceptance items to agree with the selected engineering and manufacturing partner. They are a checklist, not a claim that a particular board has already passed these checks.
Design handoff
- Revision-controlled schematic, BOM, and approved vendor list
- PCB stackup, copper weight, thermal-via, and keep-out notes
- Operating limits and critical-to-quality characteristics
Prototype validation
- Loss and temperature results with test conditions recorded
- Bus overshoot, regeneration, and protection checks
- Motor, encoder, firmware, and fault-response test coverage
Pilot release
- DFM/DFT closure and AOI inspection scope
- Functional-test fixture, limits, and pass/fail records
- Lot traceability, approved substitutions, and release package
For manufacturing workflow and quality-record context, see GanServo quality evidence and the robot-joint BOM and OEM handoff guide. For controller integration, review the 24V GaN FOC controller PCBA.
Frequently asked questions
Estimator
What does the thermal estimator calculate?
It estimates steady-state junction temperature for the hottest switch from the device loss, junction-to-ambient thermal resistance, local ambient temperature, and datasheet junction limit that you enter. It does not estimate motor current, inverter loss, or PCB temperature.
Where should the loss and thermal-resistance values come from?
Use a device-level loss calculation or measurement for the worst-case switch, plus thermal-resistance data that represents the same device and a comparable PCB, enclosure, and airflow. A generic board-area conversion is not a reliable substitute.
Are the example numbers measured GanServo results?
No. The example values only demonstrate the equation. They are not measurements, specifications, or a thermal prediction for a GanServo product.
Does a result below the entered junction limit mean the board is safe?
No. It only means the first-order estimate is below the limit you entered. You still need a project-specific temperature margin, transient analysis, worst-case load testing, and review of nearby heat sources and component tolerances.
Electrical design
Does GaN eliminate every reverse-recovery or dead-time loss?
No. GaN power transistors do not have the silicon MOSFET body-diode reverse-recovery mechanism described in the cited TI application brief, but GaN third-quadrant conduction, dead-time, gate-driver, and parasitic losses still need to be evaluated for the selected circuit.
Does a 24V bus determine the switch voltage rating?
No. The design must account for maximum supply voltage, wiring and layout overshoot, regeneration, braking behavior, and protection thresholds. Select a device with appropriate margin after measuring or modeling the actual transients.
Can this page predict efficiency at a chosen PWM frequency?
No. Efficiency depends on the selected devices, modulation, current waveform, switching energy, gate driver, dead-time, magnetics and passives, and operating point. Compare complete assemblies using matched conditions and measured data.
How should I compare a GaN design with a silicon design?
Compare device and driver losses at the same bus voltage, phase-current waveform, switching frequency, cooling condition, and control strategy. Include EMI filtering, thermal hardware, protection, and manufacturing cost in the system comparison.
Will a higher switching frequency make the servo quieter?
Not by itself. Audible noise and torque ripple also depend on motor construction, current-loop tuning, modulation, mechanical resonance, and load. Verify acoustic and motion performance on the actual motor and control stack.
OEM validation
What should an RFQ include for a 24V servo control board?
Share the minimum, nominal, and maximum bus voltage; phase current RMS and peak profiles; regeneration behavior; motor and encoder interfaces; switching and control requirements; envelope and cooling constraints; target quantity; and required test records.
What thermal evidence should I request from a prototype build?
Ask for the operating point, ambient and cooling conditions, sensor locations, measurement method, stabilization time, device or board temperature results, and the loss or thermal model used to interpret the measurements.
What should be checked before pilot production?
Agree on revision-controlled BOM and stackup, DFM/DFT actions, component traceability, AOI scope, functional-test limits and fixture coverage, thermal and transient acceptance criteria, and the records supplied with each lot.
Does the cited TI reference design validate this 24V board?
No. The cited TI material documents its own device, test setup, or motor-inverter reference design. It explains useful design methods but does not validate a different 24V servo board or its production results.
Inquiry Email
Include target torque/speed, quantity, and delivery location.