Power electronics design, from electrical requirements to a load-tested prototype
Micro Digital Engineering provides power electronics design and engineering services: DC-DC converters, AC-DC power supplies, inverters, switching power supplies and gate drivers, with their control and protection. We design each power stage to agreed voltages, currents, load profile and thermal conditions, assemble the prototype in-house, bring it up and verify it by measurement against the test plan.
Confidential task? We sign an NDA before you share technical files.
Can you design a converter for our voltage, load and control requirements?
Yes, once the requirements are defined: input and output voltage ranges, power and load profile, efficiency and thermal limits, isolation, protection behaviour, control interface and operating environment. If some of these are still open, defining them together with a topology and feasibility study is the first stage.
When you need this
- A new product needs a power supply, converter or inverter designed for its specific load.
- An existing converter has to be redesigned: components are no longer available, losses are too high or it overheats.
- A converter fails, oscillates or trips its protection, and the cause has to be found by measurement.
- You are evaluating a change of semiconductor technology, for example from silicon IGBTs to SiC MOSFETs.
- The power stage works, but its control, protection or monitoring has to be improved.
What we design
DC-DC converters
Isolated and non-isolated converters, chosen and dimensioned for the input range, load profile, isolation and efficiency target.
AC-DC power supplies
Mains-powered supplies with rectification, power factor correction where it is required, isolation and output regulation.
Switching power supplies (SMPS)
Topology, switching frequency, magnetics and control loop chosen together, because together they set losses, size, interference and stability.
Inverters
DC-AC stages with their modulation, control and protection.
Gate drivers
Drive circuits matched to the MOSFETs, IGBTs or SiC devices, their switching behaviour, isolation and fault protection.
Resonant and high-voltage stages
Stages where switching losses, voltage stress, insulation distances or pulse parameters set the design constraints.
Thermal design
Losses estimated for each power component, cooling defined for the enclosure and ambient conditions, and temperatures measured on the prototype under load.
Control and protection
Control loops, measurement, over-current, over-voltage and thermal protection, and the interfaces to the rest of the equipment.
How power prototypes are built and verified
PCB fabrication is performed by specialised manufacturing partners. Prototype component assembly, bring-up, debugging and verification are carried out in-house by our engineering team. This keeps design decisions, practical assembly and measurement within the same engineering workflow.
For a power stage, the engineers who calculated the losses and selected the components also assemble the prototype, power it up and measure it. The test plan, agreed before testing, defines how power is applied — in steps, from limited voltage and current up to the agreed operating conditions — and what is measured at each step.
Calibrated laboratory measurement capabilities
Our laboratory performs electrical measurements, waveform analysis and functional verification using calibrated measurement equipment. All measurement instruments have undergone calibration (etalonare) and are supported by calibration certificates.
For power prototypes this includes input and output voltages and currents, power and efficiency, switching waveforms and frequencies, transient behaviour and load tests.
The applicable measurement ranges and test conditions are defined according to the engineering task.
What the measurements show
| Check | What it shows |
|---|---|
| Switching waveforms | Voltage overshoot, ringing and margins against the ratings of the power devices |
| Efficiency and losses | Whether losses fit the efficiency target and the thermal budget |
| Temperatures under load | Whether components stay within their limits at the agreed load and ambient conditions |
| Control loop response | Stability and behaviour on load and input steps |
| Start-up and shutdown | Inrush current, soft-start and sequencing |
| Protection tests | Behaviour on over-current, short circuit, over-voltage and over-temperature |
What’s included
Requirements and operating conditions, topology selection and calculations, component selection, loss and thermal calculations, magnetics specifications when custom magnetics are needed, schematics and PCB layout, PCB fabrication through a manufacturing partner, in-house prototype assembly, bring-up, load and protection tests, and revisions.
The board layout of the power stage and control boards is part of the project; as a separate order it is PCB design. Control firmware is described in embedded firmware and control. Interference problems are covered in EMI troubleshooting. Not included: series manufacturing and official certification testing by an accredited laboratory.
What you receive
| Deliverable | Format | How it is checked |
|---|---|---|
| Topology study and calculations | Document | Design review |
| Component selection, loss and thermal analysis | Document, BOM | Review, then thermal measurements on the prototype |
| Schematics and PCB design | Design files, PDF schematics | Design review |
| Magnetics specifications, when needed | Specification for the magnetics supplier | Measurements on samples |
| Control and protection firmware, when in scope | Source code with build instructions | Tests on the prototype |
| Test plan | Document agreed with you | Review and written approval before testing |
| Prototype power stage, assembled in-house | The agreed number of units | Bring-up and load tests to the test plan |
| Test report | Document | Waveforms, efficiency, temperatures and protection behaviour under the agreed conditions |
How the project runs
- Electrical, thermal and operating requirements are agreed, with acceptance criteria.
- Topology and feasibility are assessed; losses and thermal load are estimated.
- Circuit, magnetics, thermal design and PCB are developed and reviewed.
- The bare PCBs are fabricated by a manufacturing partner and the components are sourced.
- The prototype is assembled in-house and brought up in steps.
- Load, thermal and protection tests are run to the test plan.
- The design is revised and tested again where the measurements show it is needed.
- You accept the prototype against the requirements; the documentation is handed over.
See how we work.
What to send us
- The requirements from the answer above, as far as they are known today. Open parameters are defined in the first stage.
- Load profile, ambient temperature and cooling conditions.
- Size constraints and the standards the equipment must meet.
- For a redesign or a failing converter: the existing schematics or a sample, and a description of the problem.
Common questions
Do you assemble and test the power prototypes yourselves?
Yes. Bare PCBs are fabricated by specialised manufacturing partners; component assembly, bring-up, debugging and measurements on the prototype are done in-house by our engineering team.
Which power and voltage ranges do you work with?
It depends on the topology and on the test conditions the prototype requires. Send the requirements: the feasibility assessment shows whether and how the project can be done and which tests are carried out in-house.
Can you find out why our converter fails or overheats?
Yes. The cause is investigated by measurement on the existing unit, and corrective changes are proposed and verified. See electronics troubleshooting and design review.
Can you change an existing inverter from IGBTs to SiC MOSFETs?
It is possible after an assessment of the consequences: gate drive, switching speed and voltage stress, interference, thermal design and protection all change. The assessment shows what has to be redesigned and whether the change achieves your goal.
Can you help with interference from a power converter?
Yes. Investigation of interference and corrective design changes are described in EMI troubleshooting and EMC design review.
Do you handle certification?
We design to the requirements of the standards agreed for the product and prepare the documentation needed for testing. Certification testing itself is carried out by an accredited laboratory.
Do you manufacture power supplies in series?
No. Series production is carried out by a contract manufacturer of your choice or one agreed in the project, using the manufacturing files we hand over.
How is a power electronics project priced?
Each stage is priced after its scope is defined. The first stage is usually a topology and feasibility assessment with its own result.
Related services
- PCB design — power and control boards for the chosen architecture.
- Embedded firmware and control — converter control and protection logic.
- Electronics troubleshooting — failures and instability in an existing power stage.
- EMI troubleshooting — interference from switching stages.
- Test benches — load test equipment for power modules.
Discuss your power stage
Send the electrical requirements and the result you need, or describe the problem with an existing converter.
Confidential task? We sign an NDA before you share technical files.