TAK Technology
Half-bridge LLC — transformer & resonant inductor
Lr–Cr–Lm resonance gives zero-voltage switching; the transformer sets Lm with its air gap, and Lr is often integrated as leakage inductance. Choose the material by operating frequency first.
- Np／NsLLC main transformer (gapped for Lm)The worst case is at the lowest operating frequency
- LrResonant inductorSame band as the main transformer; choose the material for that band
Band → material
| Band | First choice | Alternative | Note |
|---|---|---|---|
| ≦0.3 MHz | TM83★TM80TM81 | TP40TP44TP45 | |
| 0.3–1 MHz | TM59★ | TM50ATM65★ | Only above 300 kHz |
| 1–5 MHz | TM63 | TM61 | First choice for small-size MHz transformers (lowest loss) |
| NiZn | — | — | No TAK NiZn grade listed: mainstream designs use MnZn; TAK has no 4F1-class NiZn power grade |
Transformers ≤0.3 MHz: TM8x first, chosen by optimal operating temperature range (TP as alternates); >0.3 MHz: TM5x first.
Optimal operating temperature (℃): TM83★ 25–140, TM80 25–100, TM81 25–120, TM59★ 25–100, TM63 40–80.
Suggested shapes
3D · illustrativePQChoose a series ▾
Strengths
- Optimized for switch-mode power: good ratio of volume, winding window and magnetic cross-section
- Center leg can be ground for an air gap to set AL
- Simple winding and assembly, good heat dissipation
Trade-offs
- Higher core and bobbin cost
- Moderate shielding; less convenient to mount on the PCB
3D · illustrativeER / ER+I (planar)Choose a series ▾
Strengths
- Round center leg suits thick wire; lower winding loss
- Good heat dissipation, easy winding
Trade-offs
- Weak self-shielding
- Moderate bobbin cost; less convenient to mount on the PCB
3D · illustrativeEE／ETDChoose a series ▾
Strengths
- Easiest bobbin winding and assembly
- Best heat dissipation
- Low core cost
Trade-offs
- Weak self-shielding, higher leakage flux
- Needs a bobbin; for low height use EFD
3D · illustrativeRM（Lr）Choose a series ▾
Strengths
- Saves PCB area; low height possible
- Encloses the winding: good shielding, good heat dissipation
- Center leg can be ground for an air gap to set AL
Trade-offs
- Higher core cost
- Lead-out of thick wire is limited
Where it goes
Server PSU DC/DC stage; rack 800 V→50 V
OBC (CLLC), high voltage to 12 V
Charging-station modules, telecom power, TV power