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PQ3220 SMPS Transformer 12V/7.5A Flyback Topology
PQ3220 SMPS Transformer 12V/7.5A Flyback Topology
| Model： | PQ3220 |
| Ae(mm2) : | 169 |
| Ref.Power: | 90 W |
Product Description
Product Overview
This compact high-frequency flyback transformer is purpose-built for 90 W charger and adapter front-ends that must draw from wide-range DC buses (240 V / 400 V). Built on an extended PQ3220 core with PC44 Mn-Zn ferrite, it delivers a clean 12 V / 7.5 A output while holding the peak flux density to 0.26 T — comfortably within the safe margin even at the 400 V worst case. PC44’s negative loss-temperature coefficient means core loss actually falls as the part reaches its operating temperature, eliminating thermal-runaway risk inside sealed plastic enclosures.
Key Electrical Specifications
| Parameter | Specification | Notes / Test Conditions |
|---|---|---|
| Topology | Flyback (isolated) | Single primary, parallel secondary |
| Rated Output Power | 90 W | 12 V × 7.5 A |
| Input (DC Bus) | 240 V / 400 V (dual grade) | Max flux at 400 V |
| Output | 12 V DC / 7.5 A | ±5% regulation per design |
| Switching Frequency | 50 kHz | Fixed-frequency PWM |
| Core Type | PQ3220 (extended) | Mn-Zn ferrite, Ae = 169 mm² |
| Core Material | PC44 (TDK-class) | Low-loss at ~100 °C |
| Primary Inductance | 490 µH (typ.) | Measured @ 10 kHz / 1 V |
| Max Flux Density | 0.26 T | 400 V worst-case |
| Primary DCR | 0.24 Ω (typ.) | Measured at 20 °C |
| Transformer Loss | < 3.5 W | Copper + core at rated load |
| Isolation | Per customer spec | Reinforced / basic, custom |
| Operating Temp. | −40 °C to +125 °C | Insulation class confirmed by test |
Technical Highlights & Premium Craftsmanship
1. PC44 Low-Loss Ferrite for Sealed Enclosures
PC44 exhibits its minimum core loss around 100 °C. In a sealed charger the core stabilizes in exactly this band, so losses stay low and predictable — no thermal runaway, no derating surprises.
2. Multi-Section Primary + Parallel Secondary Winding
The primary is built as three series sections and the high-current secondary as three parallel TIW windings, cutting AC resistance and leakage while improving current sharing and thermal distribution.
3. Copper-Foil Shielding & Robust Construction
1 oz copper-foil sections plus triple-insulated wire (TIW) and full varnish impregnation (含浸) suppress EMI, raise dielectric strength, and lock the assembly against vibration and acoustic noise.
4. 0.26 T Conservative Flux Margin
Operating at 0.26 T even at the 400 V input leaves generous volt-second headroom, preventing saturation during transients and start-up.
Typical Applications
- Chargers & Adapters: 90 W universal chargers, industrial power supplies, and LED-driver front-ends.
- Telecom & Networking: 12 V rail generation from 240/400 V DC distribution (PoE++, small-cell, CPE).
- Industrial Electronics: isolated DC-DC stages, motor-drive auxiliary supplies, measurement instruments.
- Renewable & Storage: low-power PCS / ESS auxiliary isolation and bias supplies.
Engineering & Customization Services
Backed by an experienced magnetics team and automotive-grade production lines, TrafoPSU provides rapid prototyping and full customization.
This PQ3220 series is avaliable for output from 5V until to 48V voltage versions, also we have complete solutions with CM Mode Chokes and Inductor.
