ISDN MAGNETICS Dual S Interface Transformers • Meet requirements for pulse template and impedance template according to ITU-T (CCITT I.430) • UL and CSA approved TM9937 • Minimum interwinding breakdown voltage of 1500 Vrms • Operating temperature range 0° C to 85° C • Qualified per Bellcore TR-TSY-000357-1 ELECTRICAL SPECIFICATIONS at 25° C Part Number Turns Ratio ± 2% Primary Inductance mH min DCR Ω max Leakage Inductance µH max Pri Sec Interwinding Capacitance pF max Distributed Parallel Capacitance pF max 2798A 1.0 : 2.5 22.0 5.0 3.5 7.5 100 100 2798B 1.0 : 2.0 22.0 5.0 3.5 6.0 100 100 2798C 1.0 : 2.0 22.0 3.75 2.25 4.45 100 80 2798D 1.0 : 2.0 22.0 2.5 3.5 6.0 100 100 2798E 1.0 : 1.0 22.0 5.0 3.5 3.5 100 40 Compatible Transceiver ICs Part Number 2798A 2798B 2798C IC Manufacturer IC Part Number Lucent T7250C T7256 T7234 Lucent T7901 T7903 Siemens PEB2081 PEB2085 PEB2086 Mitel MT8930 National Semiconductor TP3420 TP3421 2798D AMD 79C30A 79C32A 2798E Motorola MC145474 MC145475 SCHEMATIC 2798A 2798B 2798C 2798D 2798E T1 1 16 2 15 3 14 4 13 T2 5 12 6 11 7 10 8 Primary 9 Secondary ©1999 Bel Fuse Inc. Specifications subject to change without notice. 06.99 Bel Fuse Inc. 198 Van Vorst Street, Jersey City, NJ 07302 • Tel 201-432-0463 • Fax 201-432-9542 • www.belfuse.com T326 ISDN MAGNETICS Dual S Interface Transformers TM9937 MECHANICAL 2798A 2798B 2798C 2798D 2798E 0.950 [24.13] max 0.1.22 [3.10] typ 16 1 15 14 13 12 11 10 9 2 6 8 3 4 5 7 0.100 [2.54] typ 0.595 [15.11] typ 0.300 [7.62] max 0.015 [0.38] 0.705 [17.91] + 0.010 [0.25] – 0.005 [0.13] Note: Unless otherwise specified, dimensions are nominal and in inches [millimeters]. 0.030 [0.76] Terminal Pad 0.035 [0.89] 0.755 [19.18] typ 0.060 [1.52] typ 0.060 [1.52] typ 0.100 [2.54] typ Suggested PCB Pad Layout Tape and reel packaging: 400 parts/reel ©1999 Bel Fuse Inc. Specifications subject to change without notice. 06.99 CORPORATE FAR EAST EUROPE Bel Fuse Inc. 198 Van Vorst Street Jersey City, NJ 07302 Tel 201-432-0463 Fax 201-432-9542 www.belfuse.com Bel Fuse Ltd. 8F / 8 Luk Hop Street San Po Kong Kowloon, Hong Kong Tel 852-2328-5515 Fax 852-2352-3706 www.belfuse.com Bel Fuse Europe Ltd. Preston Technology Management Centre Marsh Lane, Suite F23, Preston Lancashire, PR1 8UD, U.K. Tel 44-1772-556601 Fax 44-1772-888366 www.belfuse.com T327