Ferrites and accessories EFD 20/10/7 Core and accessories Series/Type: B66417, B66418 Date: June 2013 Data SheetData Sheet EPCOS AG 2013. Reproduction, publication and dissemination of this data sheet and the information contained therein without EPCOS prior express consent is prohibited.EFD 20/10/7 Core B66417 E core with flattened, lower center leg for especially flat transformer design For DC/DC converters Delivery mode: single units Magnetic characteristics (per set) 1 l/A = 1.52 mm l = 47 mm e 2 A = 31 mm e 2 A = 31 mm min 3 V = 1460 mm e Approx. weight 7.2 g/set Ungapped Material A value P Ordering code L e V nH W/set N49 910 +30/20% 1100 < 0.29 ( 50 mT, 500 kHz, 100 C) B66417G0000X149 N87 1200 +30/20% 1440 < 1.05 (200 mT, 100 kHz, 100 C) B66417G0000X187 N97 1250 +30/20% 1510 < 0.80 (200 mT, 100 kHz, 100 C) B66417G0000X197 Gapped Material A value g Ordering code L e nH approx. mm N87 100 10% 120 0.49 B66417U0100K187 160 10% 193 0.25 B66417U0160K187 The A value in the table applies to a core set comprising one ungapped core (dimension g = 0) and L one gapped core (dimension g > 0). Calculation factors (for formulas, see E cores: general information ) Material Relationship between Calculation of saturation current air gap A value L K1 (25 C) K2 (25 C) K3 (25 C) K4 (25 C) K3 (100 C) K4 (100 C) N87 61.1 0.699 85.4 0.796 75.7 0.873 Validity range: K1, K2: 0.10 mm < s < 1.40 mm K3, K4: 50 nH < A < 410 nH L Please read Cautions and warnings and 2 06/13 Important notes at the end of this document.