A two-unit family of surface-mount magnetic transformer modules conforming to IEEE 802.3u standards boasts an extended temperature range of -40°C to 85°C. They interface with all major IC manufacturers' transceivers that meet industrial Ethernet temperature specifications, including Level One's LXT971 and AMD's NetPHY-1LP physical layer (PHY) and PCnet-Fast+ controller devices. The S558-5999-U5 transformer creates maximum EMI noise suppression as it has an added auto transformer to support termination of the unused twisted pair. These single-port SMT devices also meet all ANSI standards, including 350 µH OCL with 8 mA bias and provide an isolation voltage of 1,500 Vrms. Price for S558-5999-T5 and S558-5999-U5 is $5 each/10,000.