TDK released the ALT3232M, presented as the world's smallest SMD pulse transformer for LAN applications, measuring 3.2 x 3.2 x 2.8 mm3. 30% lower in volume and footprint than previous products, the inductance of the new transformer is 150 μH, its insertion loss is in the frequency range from 100 kHz to 100 MHz at 2.5 dB, and its parasitic winding capacitance is only 25 pF at 100 kHz. Series production will start in July 2013. The number of pulse transformers used in LAN applications is increasing in response to the raised transmission speed of Ethernet networks, namely from 100 to 1000 Mbps. In addition, several transformers are usually placed on a circuit board, so that minimized component dimensions are of crucial importance. LAN interfaces are not only used in computers and other IT equipment, but increasingly also in LCD TV sets and other audiovisual appliances. They transmit the pulse-shaped signals at high transmission speeds and at the same time provide electrical insulation between input and output. By applying technology that has proved its worth in the production of SMD common mode filters, TDK was able to devise an automated winding process suitable for mass production. This reduces characteristics variations that tend to occur with manual winding, and thereby offers enhanced reliability and quality. TDK
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