PQ2020 PQ2625 PQ3230 PCB Mount High Frequency Transformer For SMPS And Inverter
The PQ series high frequency transformer is a switching transformer family built on PQ type ferrite cores, available in PQ2020, PQ2625 and PQ3230 sizes. The PQ core is designed to give a large effective cross-section and a large winding window while keeping the PCB footprint compact, and its round centre leg allows a short mean turn length. The result is lower copper loss, better winding space utilisation and a higher power density than an EE or EI transformer occupying a similar board area, which is why the PQ shape is often chosen for LLC resonant converters, high-efficiency adapters and industrial power supplies.
All three sizes share the same design logic. The transformer is wound on a horizontal or vertical bobbin with full copper enamelled wire, the primary and secondary are separated by margin tape or triple insulated wire depending on the isolation requirement, and the assembly is varnish impregnated to reduce audible noise and improve moisture resistance. Turns ratio, inductance, pin configuration, creepage distance, wire type and insulation class are all engineered to the customer's schematic rather than sold as a fixed catalogue item.
PQ2020 covers compact adapters and mid power converters, PQ2625 handles higher power in LED drivers, chargers and inverters, and PQ3230 extends the range further for industrial supplies and solar or charging equipment. Every unit is 100% tested for inductance, turns ratio and hi-pot before packing, and production runs in our own factory under an ISO 9001 quality system.
| Item | PQ2020 | PQ2625 | PQ3230 |
|---|---|---|---|
| Core Size Code | PQ2020 | PQ2625 | PQ3230 |
| Relative Size | Smallest footprint in this series | Medium footprint | Largest footprint in this series |
| Relative Power Class | Mid power | Higher power | Highest in this series |
| Typical Pin Count | 5+5 to 6+6 | 6+6 to 7+7 | 7+7 to 8+8 |
| Typical Use | Compact adapters, DC-DC converters, LLC resonant modules | LED drivers, fast chargers, inverter auxiliary supplies | Industrial power supplies, solar inverters, charging equipment |
| Exact Core Dimensions | Confirmed on approved drawing | Confirmed on approved drawing | Confirmed on approved drawing |
| Rated Output Power | Confirmed on approval sample | Confirmed on approval sample | Confirmed on approval sample |
| Parameter | Specification |
|---|---|
| Product Type | High frequency switching transformer, PQ series, PCB mount |
| Available Sizes | PQ2020, PQ2625, PQ3230 |
| Core Material | Ferrite, PC40 / PC44 standard; N87 / N97 / PC95 low-loss material on request |
| Core Shape Benefit | Round centre leg with a short mean turn length, giving low copper loss and high power density |
| Bobbin Material | UL94V-0 phenolic or PBT, horizontal or vertical type |
| Pin Configuration | 5+5 to 8+8 depending on core size; custom pin pitch and pin length available |
| Operating Frequency | 20 kHz to 200 kHz standard; up to 500 kHz with Litz wire and low-loss core |
| Applicable Topology | LLC resonant, flyback, forward, half-bridge, full-bridge and push-pull |
| Primary Inductance (Lp) | Built to customer specification, standard tolerance +/-10%; +/-5% or +/-3% available |
| Leakage Inductance | Typically below 3% of Lp; below 1.5% with sandwich winding structure. Resonant designs can be built to a specified leakage value |
| Turns Ratio & Windings | Built to customer schematic; multi-output, auxiliary and bias windings supported |
| Winding Wire | Class 155 (F) enamelled copper wire; triple insulated wire (TIW), Litz wire or copper foil on request |
| Insulation Class | Class B (130 C) or Class F (155 C) standard; Class H (180 C) available |
| Isolation / Hi-Pot | 3000 V AC for 1 minute, primary to secondary; 4000 V AC reinforced isolation on request |
| Air Gap | Centre leg gap ground to the target AL value; ungapped option available for forward and resonant designs |
| Temperature Rise | Not more than 40 K at rated load under the agreed test condition |
| Operating Temperature | -40 C to +130 C |
| Impregnation | Varnish dipped to reduce audible noise and improve moisture resistance |
| Mounting | Through-hole PCB mounting; SMD base, flying leads or bracket versions available |
| Testing | 100% inductance, turns ratio and hi-pot test; sampling test for temperature rise |
| Compliance | RoHS compliant, UL94V-0 materials, UL-recognized wire; CE / CB / UL documentation support |
| Packaging | Anti-static tray or blister packing inside strong export cartons |
| Customization | Core size, turns ratio, inductance, leakage target, pin layout, wire type, insulation class and marking all customizable, OEM and ODM welcome |
| MOQ / Sample | MOQ 1,000 pcs; samples available before mass production |
- PQ core geometry combines a large effective cross-section with a compact PCB footprint, giving higher power density than an EE transformer occupying similar board area.
- Round centre leg shortens the mean turn length, which lowers copper loss and helps the transformer run cooler at the same output power.
- Well suited to LLC resonant designs: the leakage inductance can be built to a specified target value and used as part of the resonant network.
- Three sizes in one family - PQ2020, PQ2625 and PQ3230 - let you scale power up or down while keeping the same construction, supplier and quality standard.
- Selectable insulation solution: margin tape construction for cost-sensitive designs, or triple insulated wire for reinforced isolation and tighter coupling.
- Controlled air gap ground to the target AL value, so inductance and energy storage behaviour stay repeatable between batches.
- Optional sandwich winding and Litz wire to control leakage inductance, skin effect and proximity effect at higher switching frequencies.
- Full copper winding with controlled tension keeps inductance and DCR consistent across large production runs.
- Varnish impregnation suppresses winding movement, so the transformer stays quiet and resists humidity.
- Flexible pin layout: pin count, pin pitch and creepage distance are matched to your existing PCB footprint, so no board redesign is needed.
- Materials to UL94V-0 flame-retardant grade and RoHS requirements, supporting your own safety approval work.
- 100% electrical testing on every unit before packing, with test data available on request.
- LLC resonant converters and high-efficiency AC-DC power supplies.
- Power adapters and chargers: desktop adapters, fast chargers, USB PD chargers, laptop and monitor supplies.
- LED lighting: constant-current LED drivers, high bay and street light power modules, panel light supplies.
- Renewable energy: solar inverters, energy storage converters, battery charging and management modules.
- Industrial control: PLC power modules, drive control boards, automation cabinets, welding and machine tool supplies.
- Communication and IT: server and telecom power units, network equipment supplies, base station auxiliary power.
- Charging equipment: EV charging modules, portable chargers and charging pile auxiliary supplies.
- Home and commercial appliances: induction cookers, air conditioners, vending machines, commercial kitchen equipment.
- Instrumentation and medical electronics requiring reinforced isolation and stable electrical performance.
- General purpose DC-DC converters and switch mode power supplies in the mid to higher power range.
- Established in 2000, with 26 years focused on magnetic components for industrial control and power electronics; we are a manufacturer, not a trading company.
- Self-owned 10,000 square metre factory with 8 complete production lines, which keeps lead times and quality consistent on repeat orders.
- A 20-person R&D team supports you from schematic review and sample building through to mass production, and a 20-person QC team controls the process.
- Complete certification framework: ISO 9001 and ISO 14001 system certification, with CE, CB, UL, cUL and RoHS product certification available.
- Annual export value of USD 42 million, shipping to North America (50%), Northern Europe (18%), South America (15%) and Southeast Asia (15%), including OEM customers such as Midea and Federal Signal.
- Flexible cooperation: MOQ from 1,000 pcs, DDP and DDU terms supported, direct factory delivery.
- One supplier covers the whole PQ range, so you can standardise construction, insulation system and quality criteria across several products instead of qualifying three different vendors.
- Fully customised design instead of a standard part: the transformer is matched to your controller IC, input voltage range, topology and output requirement.
- Leakage inductance can be specified and controlled, which is critical for LLC resonant designs where the transformer is part of the resonant tank.
- High power density lets you keep the same output power in a smaller board area, or increase power without enlarging the enclosure.
- Consistent gap grinding and winding process reduce inductance drift between batches, keeping loop behaviour predictable in mass production.
- Safety-oriented construction with reinforced isolation options supports your certification work in export markets.
- Free engineering support before the design is frozen: send us your schematic and target specification and we will recommend the most suitable core size in the series.
Get in Touch
Have questions about our products or want to discuss a custom order? Our team is ready to help you.

