News and New Products

“Terminator” causes no panic, keeps fast signals from coming back

By Bill Schweber -- EDN, 7/6/2005

For high-speed digital lines, the CHC series of termination networks from the IRC Division of TT Electronics maintains maximum signal integrity with nine Thevenin pairs in an 18-resistor array. According to Jerry Seams, application manager, “The terminators provide both pullup and pulldown functions, and the BGA package eliminates wire bonds, reducing parasitic capacitance.” These Thevenin pairs typically find use in DDR memory, ECL/PECL (emitter-coupled-logic/positive-ECL) and single-ended and differential-signal terminations (Picture).

The vendor fabricates the devices from tantalum nitride thin-film elements, and they resist the corrosion that may occur with nichrome elements in humid applications. Absolute TCR (temperature coefficient of resistance) is ±100 ppm/°C. The elements are available in a wide range of values, as standard or custom orders, with the BGA package in a JEDEC-standard 8-9A size. The price is less than $1 (10,000).

TT Electronics IRC Advanced Film Division, www.irctt.com.