Telephone Line Coupling Modem Transformer at 56K/124Kbps
High performance telephone line modems increase data transmission speed up to
56K Bits/second in ITU / CCITT protocol standards V.90 (X2 or K56flex) and V.92. Integrity
Technology Corporation offers T14H low profile coupling transformers for 56Kbps
modem applications. This top quality high performance transformer using EI 14mm Nickel Alloy core
are very compact size at 0.49" in height, 0.57 Width and 0.52" in depth. Transformers are made with top quality
thermal molded Phenolic bobbins with hard copper pins. These telephone line impedance matching
transformers are designed for direct connect to 600 Ohms telephone line with zero
DC bias, in "Dry" modem circuits. Integrity Technology also offers T24Z full size
56K and 64Kbps and dual line 124Kbps modem coupling transformers.
Integrity Technology Corporation also manufactures other low cost Voice band Telephone Matching Transformers.
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ADDITIONAL MODEM TRANSFORMERS BACKGROUND INFORMATION
Modem transformers, often called telephone line coupling transformers or
audio matching transformers, are key components to connect to telephone lines and telephone networks. Typical
applications are Modem, FAX/Modem, FAX Machines, Telephone, answering machines, silent
alarms, credit card verification machines ... etc. The latest generation of advance and low cost
telephone coupling transformers, usually PCB through hole mounted, offer several major key
criteria for engineers and designers to select from:
Low profile of about half an inch above printed circuit board, usually between 0.35" to 0.55"
for different horizontal mounted EE transformer cores and bobbin sizes,
Very Low cost at moderate volume 10K pieces, for high performance of
28.8, 33.6 and 56K bps modem/FAX data transmission rates.
These transformers are manufactured using top quality Phenolic bobbins with molded hard copper
pins for best PCB assembly production, compare with Glass filled Nylon bobbins with soft wire leads transformers.
Small and compact footprint of between 0.15 to 0.20 square inches, would help conserve
printed circuit board real estates,
Dry input circuit of 0mA DC bias current at primary winding for Direct telephone line data
interface, and for Wet circuit of 50mA to 110mA DC bias loop current.
High performance core material, Z11 Nickel Permalloy, offer high to moderate permeability,
High Q, and high flux density. Other Grain oriented or non-oriented Silicon Steel
lamination cores, offer low output signal distortion, and wide frequency spectrum. Typical
EE core sizes are of 12, 14, 16 & 24mm.
Input primary winding current rating for EIA-470 Ringing duty cycle requirement of
minimum 125mA and continuous UL rating of 80mA.
Integrity Technology Corporation offers complete series of compact low profile, high performance telephone
coupling transformers at most competitive cost. The T14H and T24Z modem transformers, designed for CCITT V.90 standard 56Kbps
modem application has 1 : 1 turn ratio, height of 0.49" and current rating of 50mA. Their T16Z transformers have
height of 0.58", primary bias DC loop current of 50mA to 90mA and current rating of 80mA, is popular voice band
coupling transformer for low cost telephone applications.
