The SN74GTLPH1612 is a high-drive, 18-bit UBTTM transceiver that provides LVTTL-to-GTLP and GTLP-to-LVTTL signal-level translation. It allows for transparent, latched, clocked, or clock-enabled modes of data transfer. The device provides a high-speed interface between cards operating at LVTTL logic levels and a backplane operating at GTLP signal levels. High-speed (about three times faster than standard TTL or LVTTL) backplane operation is a direct result of GTLP's reduced output swing (<1 V), reduced input threshold levels, improved differential input, OECTM circuitry, and TI-OPCTMcircuitry. Improved GTLP OEC and TI-OPC circuits minimize bus-settling time and have been designed and tested using several backplane models. The high drive allows incident-wave switching in heavily loaded backplanes with equivalent load impedance down to 11 . GTLP is the Texas Instruments (TITM) derivative of the Gunning Transceiver Logic (GTL) JEDEC standard JESD 8-3. The ac specification of the SN74GTLPH1612 is given only at the preferred higher noise margin GTLP, but the user has the flexibility of using this device at either GTL (VTT = 1.2 V and VREF = 0.8 V) or GTLP (VTT = 1.5 V and VREF = 1 V) signal levels.