TAK Technology
Boost converter — input inductor
The inductor sits on the input side and its average current equals the input current (larger than the output current); the worst case is at the lowest input voltage.
- LBoost storage inductorCheck saturation at minimum input voltage and maximum load; adjust AL with the air gap
Band → material
| Band | First choice | Alternative | Note |
|---|---|---|---|
| ≦0.1 MHz | TM82 | — | Bs 600 mT, gapped for DC bias |
| 0.1–0.5 MHz | TM71 | — | By IDC: μi 3800 + high Bs |
| 0.5–0.8 MHz | TM59★ | — | |
| 0.8–3 MHz | TM65★ | TM61 | |
| ≦0.3 MHz | — | TM80TM83★ | When loss matters; high temperature (core up to 140 ℃) |
| NiZn | — | — | No TAK NiZn grade listed: high-current / high-flux designs use MnZn; for mA-level parts see SMD HF low-power inductors |
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 · illustrativeRMChoose 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
3D · illustrativeERChoose 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 · illustrativeToroid TChoose a series ▾
Strengths
- Closed magnetic path without joints or air gap: highest magnetic efficiency
- Good self-shielding, low leakage flux
- Lowest core cost, no bobbin needed
Trade-offs
- Winding must be threaded through the hole; high winding cost
- Less convenient to mount on the PCB
- No air gap; for storage inductors use a combination shape whose gap can be ground
Where it goes
Backup-battery boost
Storage inductors for 48 V mild-hybrid bidirectional DC/DC
Solar MPPT, LED drivers, battery boost