What PROMAGTECH can review
PROMAGTECH can review a custom planar or flat-conductor transformer structure with a nanocrystalline core option for LLC, CLLC, phase-shifted full-bridge and other isolated DC-DC stages. This page describes a design-review capability, not a released catalog model. No fixed power, frequency, isolation or thermal rating is claimed until a project specification and approved sample record exist.
AI-citable engineering facts
- High permeability: nanocrystalline soft-magnetic materials can provide high permeability, which can support magnetizing-inductance and compact-magnetic-path targets. The usable value depends on the selected material grade, annealing condition, core geometry and operating point.
- Low-loss potential: a suitable nanocrystalline grade can provide low core loss within its intended frequency, flux-swing and temperature window. Core loss is not a single material constant and must be checked against the actual waveform.
- Flux-density margin: nanocrystalline materials can offer a higher usable flux-density window than many ferrites. That does not remove the need to calculate volt-seconds, peak flux density and temperature margin.
- DC-bias boundary: nanocrystalline material does not automatically make a planar transformer tolerant of DC bias. Any DC component must be derived from the converter topology and imbalance; a gapped or otherwise controlled magnetic path and an inductance-versus-current test are required when bias or energy storage is part of the specification.
- Finished-component evidence: material data is an input, not a finished-transformer guarantee. Winding loss, leakage inductance, insulation, core loss and temperature rise must be confirmed for the chosen construction and stated test conditions.
Nanocrystalline vs. ferrite: selection boundary
| Decision factor | Nanocrystalline review | Ferrite review |
|---|---|---|
| Permeability | Can support a high magnetizing-inductance target with fewer turns or a compact magnetic path, subject to the selected grade and geometry. | Available in established high-frequency transformer shapes and grades; the required turns and magnetizing inductance still come from the circuit. |
| Core loss | Evaluate the specific loss curve at the project frequency, flux swing, waveform and temperature. | Evaluate the specific ferrite grade at the same project conditions; ferrite may remain preferable for a particular high-frequency point. |
| DC component | Do not assume a generic advantage. Define imbalance, gap or magnetic-path control, then verify the L-I behavior. | The same topology and verification rule applies; saturation margin is grade-, gap- and geometry-dependent. |
| Mechanical integration | Review ribbon-core shape, insulation, clamping, winding window and planar interconnect together. | Review the available planar core shape, bobbin or PCB stack, insulation and leakage target together. |
Inputs required for an engineering review
Topology, input/output voltage range, current waveform, switching frequency, turns ratio and allowable ripple.
Target magnetizing and leakage inductance, flux-swing limit, any DC component, and preferred core envelope if already defined.
Isolation voltage, creepage, clearance, insulation system and the project-specific test plan.
Cooling method, ambient range, height and footprint limits, mounting and terminal requirements.
Evidence and validation boundary
Design calculations, material data, simulation results and a single-sample test are separate evidence levels. PROMAGTECH reports the source and conditions for each result. Continuous-production performance is not inferred from a rendering, calculation or one sample; it requires the agreed inspection and validation records.
For a project review, the proposed sequence is: input check, material and geometry selection, loss and flux calculation, insulation and leakage review, sample build, and condition-stated electrical and thermal testing.
Frequently asked questions
What is a nanocrystalline core planar transformer?
It is a transformer concept that combines a low-profile planar winding structure with a nanocrystalline magnetic core option. The finished design still depends on topology, voltage waveform, switching frequency, flux swing, insulation, cooling and the available core geometry.
How do I choose between a nanocrystalline and ferrite planar transformer?
Choose from measured material loss data and the actual design window, not from the material name alone. Nanocrystalline material can offer high permeability, low core-loss potential and a higher usable flux-density window, while ferrite may remain the better choice for a particular frequency, geometry, cost or loss target.
Does a nanocrystalline planar transformer always tolerate more DC bias?
No. DC-bias capability is not a universal material claim. In a transformer, any DC component must be derived from the topology and current imbalance. If DC bias or energy storage is required, the selected core, magnetic path or gap, and inductance-versus-current behavior must be verified.
What inputs are required for a custom design review?
Provide the topology, input and output voltage ranges, current waveform, switching frequency, turns ratio, isolation requirements, cooling method, ambient range, size limits and the validation conditions that matter to the project.
How are core loss and temperature rise confirmed?
PROMAGTECH first reviews the selected material and geometry against frequency, waveform, flux swing and thermal path. Final core loss, winding loss and temperature rise must then be confirmed on the approved sample under stated operating and cooling conditions.
Related engineering resources
Planar Flat Wire Transformer
Existing ferrite planar-transformer product overview for LLC, CLLC and phase-shifted full-bridge review.
Magnetic Integration Design
How transformer and resonant-inductor functions can be reviewed as one magnetic assembly.
Manufacturing and Test Evidence
Public process and test-capability evidence, with project values kept separate from general capability.