The 'GTL16612A devices are 18-bit universal bus transceivers (UBT) that provide LVTTL-to-GTL+ and GTL+-to-LVTTL signal-level translation. They allow for transparent, latched, clocked, or clock-enabled modes of data transfer. These devices provide a high-speed interface between cards operating at LVTTL logic levels and backplanes operating at GTL+ signal levels. High-speed (about two times faster than standard LVTTL or TTL) backplane operation is a direct result of the reduced output swing (<1 V), reduced input threshold levels, and output edge control (OECTM). Improved GTL+ OEC circuits minimize bus settling time and have been designed and tested using several backplane models. VTT