Planar Cores (7878400321)Part Number: 7878400321
78 PLANAR EI CORE SET
Planar EE and EI cores, with their low profile are suitable for board level installation allowing assembly without the need for plastic coilformers and can also allow windings integrated into multi-level PCBs. Planar ER cores with their low mass and low profile are suitable for Surface Mount installations in low power filter and transformer applications.
Planar EE, ER and EI cores can be supplied with the center post gapped to a mechanical dimension, or an AL value.
Weight: 10.5 (g)
| Dim | mm | mm tol | nominal inch | inch misc. |
| A | 21.8 | ± 0.40 | 0.858 | _ |
| B | 5.7 | ± 0.15 | 0.224 | _ |
| C | 15.8 | ± 0.35 | 0.622 | _ |
| D | 3.2 | ± 0.15 | 0.126 | _ |
| E | 16.8 | ± 0.40 | 0.661 | _ |
| F | 5 | ± 0.20 | 0.197 | _ |
| G | 2.5 | ± 0.15 | 0.098 | _ |
Chart Legend
Σl/A : Core Constant, le : Effective Path Length, Ae : Effective Cross-Sectional Area, Ve : Effective Core Volume
AL : Inductance Factor 
Explanation of Part Numbers: Digits 1 & 2 = product class and 3 & 4 = material grade.
| Electrical Properties | |
| AL(nH) | 5400 ±25% |
| Ae(cm2) | 0.79 |
| Σl/A(cm-1) | 3.3 |
| le(cm) | 2.61 |
| Ve(cm3) | 2.06 |
| Amin(cm2) | 0.79 |
AL value is measured at 1 kHz, B < 10 gauss.