ER cores (also known as EER cores) are a low-cost option for inductor and transformer applications. The cores have a form that substantially eliminates winding resistance while maintaining efficiency. Nonetheless, ER cores are more expensive than E cores, despite their lesser output. You can buy them in a variety of sizes, including EER2811/EER3511/EER4215 etc. EER cores have numerous uses, including differential inductors and power transformer
| Type | Fig | DIMENSIONS (mm) | Effective Parameters | AL (nH)+30% -20% | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| A | B | c | D | E | F | Le(mm) | Ae(mm²) | CF196 | CF139 | ||
| EER5322 | 7 | 53 ± 0.8 | 23.2 ± 0.3 | 39.4 ± 0.7 | 16.3 ± 0.2 | 19.9 ± 0.3 | 21.5 ± 0.3 | 107 | 315 | 5950 | 6250 |
| EER4518A | 7 | 45 ± 0.9 | 17.5 ± 0.2 | 33.8 ± 0.8 | 10.95 ± 0.25 | 17.6 ± 0.4 | 17.6 ± 0.4 | 81 | 232 | 6150 | 6400 |
| EER4217 | 7 | 42.15 ± 0.65 | 17.5 ± 0.15 | 25 ± 0.15 | 30.3 ± 0.5 | 17.3 ± 0.25 | 17.3 ± 0.25 | 107 | 240 | 4500 | 4600 |
| EER4215 | 7 | 42.15 ± 0.8 | 31.0 min. | 21.6 ± 0.2 | 15.95 ± 0.35 | 15.1 ± 0.4 | 15.1 ± 0.4 | 99 | 177 | 3500 | 3600 |
| EER3913 | 7 | 39 ± 1.4 | 28.6+1.0 | 22.2 ± 0.2 | 17 ± 0.25 | 12.8 ± 0.2 | 12.8 ± 0.2 | 101 | 131 | 2750 | 2850 |
| EER3511 | 7 | 35 ± 0.5 | 25.6+1.0 | 22.5 ± 0.3 | 16.5 ± 0.3 | 11.3 ± 0.3 | 11.3 ± 0.3 | 97 | 111 | 2600 | 2750 |
| EER3511B | 7 | 35 ± 0.5 | 25.6 ± 1 | 20.7 ± 0.3 | 14.7 ± 0.3 | 11.3 ± 0.3 | 11.3±0.3 | 89.6 | 110 | 2600 | 2700 |
| EER2811 | 7 | 28.5+0.6-0.5 | 21.2 min. | 16.9±0.25 | 12.5+0.3-0.25 | 9.9±0.25 | 11.4±0.25 | 75 | 83 | 2300 | 2400 |
| EER2811A | 7 | 28.5+0.6-0.5 | 21.2 min. | 14.0±0.2 | 9.65±0.25 | 9.9±0.25 | 11.4±0.25 | 64 | 82 | 2750 | 2900 |
| EER2811B | 7 | 28.5+0.6-0.5 | 21.2 min. | 21.4±0.3 | 15.4±0.3 | 9.9±0.25 | 11.4±0.25 | 50 | 78 | 3300 | 3400 |
