FROM EDN EUROPE: PHY chip defeats Cat5 wiring fumbles
by Graham Prophet -- EDN, May 12, 2005
Micrel's KS8001 is a physical medium (line driver) chip for 10/100 Ethernet applications, covering 10BASE-T, 100BASE-TX and 100BASE-FX formats. Described as a fifth-generation part, it includes a function called LinkMD (the "MD" being an allusion to the American abbreviation for a doctor) that detects and where possible corrects common wiring problems with Category 5 cabling. The chip automatically corrects polarity reversal as well as incorrect use of a straight-connect cable where a cross-over cable is required, and vice-versa, and provides normal operation. It employs HP Auto-MDIX switching to implement this function.
Where the fault is fatal to the link operation, the chip provides diagnostic information by using time-domain reflectometry to notify the distance to an open- or short-circuit in the loop. The information the chip reports from the LinkMD module extends to distance-to-impedance-mismatch, where (for instance) a poorly wired or incorrect connector has been placed in the loop. The chip reports information for fault distances of up to 200m, 1m, greatly simplifying the task of debugging installations.
The KS8001 operates at a core voltage of 1.8V, for a power consumption of 200 mW, and will be priced at $2.61 (1000).
Micrel, 33 1 60 92 41 90, www.micrel.com
