EPCOS, represented in Australia by Ramelec , has made interface transformers for DSL equipment smaller. The improvements were obtained by careful calculation of the magnetic form factor and winding space.
In comparison with the EP7-based transformer, the new transformer with the EP5XL core is 25% smaller in area (64.5mm2), 31% lower in height (7 mm) and 48% smaller in volume (451.5m3).
Comparison of type B78416A1850A003 (EP5XL) with its predecessor B78417A1764A003 (EP7) shows that despite its smaller core volume the transformer has the same longitudinal balance and total harmonic distortion (THD) values while satisfying the leakage inductance requirements). Only its ohmic resistance is higher.
The transformer can satisfy the requirements for surge voltage strength and is designed for 2.5 kV/2/10µs or 1.5 kV/10/700µs. The higher ohmic resistances can be compensated by next-generation line card chips. EPCOS is currently developing variants for several DSL chipsets. Customer-specific versions are available on request.