ISDN MAGNETICS
Dual S InterfaceTransformers
TM9937
•
•
Meet requirements for pulse template and impedance
template according to ITU-T (CCITT I.430)
•
•
•
Minimum interwinding breakdown voltage of 1500 Vrms
Operating temperature range 0° C to 85° C
Qualified per Bellcore TR-TSY-000357-1
UL and CSA approved
ELECTRICAL SPECIFICATIONS at 25° C
DCR
Ω
max
Distributed
Primary
Inductance
mH min
Leakage
Inductance
µH max
Interwinding
Capacitance
pF max
Turns Ratio
Parallel
Capacitance
pF max
Part Number
± 2%
Pri
Sec
2798A
2798B
2798C
2798D
2798E
1.0 : 2.5
1.0 : 2.0
1.0 : 2.0
1.0 : 2.0
1.0 : 1.0
22.0
22.0
22.0
22.0
22.0
5.0
5.0
3.5
3.5
7.5
6.0
100
100
100
100
100
100
100
80
3.75
2.5
2.25
3.5
4.45
6.0
100
40
5.0
3.5
3.5
SCHEMATIC
T1
Compatible Transceiver ICs
IC Manufacturer IC Part Number
16
1
Part Number
2798A
2798B
2798C
2798D
2798E
T7250C
T7256
T7234
2798A
2798B
Lucent
Lucent
2
3
15
14
T7901
T7903
4
5
13
12
PEB2081
PEB2085
PEB2086
Siemens
Mitel
T2
2798C
MT8930
National
Semiconductor
TP3420
TP3421
6
7
11
10
79C30A
79C32A
2798D
2798E
AMD
MC145474
MC145475
8
9
Motorola
Primary
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
