HIGH FREQUECY MAGNETICS T1/E1 Surface Mount Transformer • Operates at the T1 rate of 1.544 Mbits/s and at the E1 rate of 2.048 Mbits/s • Designed for transmit and receive line interface applications • Low capacitance design for EMI suppression • Dual ratio for both 75Ω and 120Ω operation • 1500-Volt isolation TM00139 • Operating temperature range: -40° C to +85° C • Meets IEC 695, 2-2 flammability requirements • PWB Process Capability: standard printed wiring board assembly techniques, total-immersion cleaning • Reliability testing: Shock, vibration, temperature cycling, temperature - humidity - bias ELECTRICAL SPECIFICATIONS AT 25° C Part Number 2779H Nominal Turns Ratio ±2% DCR Inductance1 mH min Leakage Inductance 2 µH max & min Ω max Interwinding Capacitance3 pF max (4-1):(5-2) (4-1):(5-8) (4-1) (4-1) (5-2) (3-8) (4-1) (4-1) & (5-2) (4-1) & (3-8) 1 : 1.07 1 : 1.37 1.65 1.1 1.1 0.4 0.70 26 28 Minimum Interwinding Breakdown Voltage Vrms 1500 1. measured at 10 kHz, 0.1 Vac 2. measured at 100 kHz, 0.10 Vac 3. measured at 1 kHz, 1 Vac SCHEMATICS 2779H 4 5 2 3 1 8 1 : 1.07 1 : 1.37 ©2000 Bel Fuse Inc. Specifications subject to change without notice. 09.00 Bel Fuse Inc. 198 Van Vorst Street, Jersey City, NJ 07302 • Tel 201-432-0463 • Fax 201-432-9542 • www.belfuse.com T1-87 HIGH FREQUECY MAGNETICS T1/E1 Surface Mount Transformer TM00139 MECHANICAL 2779H 8 7 6 5 8 7 6 5 1 2 3 4 0.256 (6.50) TERMINAL 1 IDENTIFIER 1 2 3 4 0.160 (4.06) 0.350 (8.89) MAX 0.050 (1.27) 0.100 (2.54) 0.004 8 EDGES 0.100 1 2 3 4 0.490 (12.45) MAX 0.430 (10.92) MAX 0.500 (12.7) MAX Unless otherwise specified, dimensions are nominal and in inches (millimeters). ©2000 Bel Fuse Inc. Specifications subject to change without notice. 09.00 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 G7, Preston Lancashire, PR1 8UD, U.K. Tel 44-1772-556601 Fax 44-1772-888366 www.belfuse.com T1-88