The user has the flexibility of using this device at either GTL (VTT = 1.2 V and VREF = 0.8 V) or the preferred higher noise margin GTL+ (VTT = 1.5 V and VREF = 1 V) signal levels. GTL+ is the Texas Instruments derivative of the Gunning transceiver logic (GTL) JEDEC standard JESD 8-3. The B port normally operates at GTL or GTL+ signal levels, while the A-port and control inputs are compatible with LVTTL logic levels and are 5-V tolerant. VREF is the reference input voltage for the B port. Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. OEC and Widebus are trademarks of Texas Instruments Incorporated. Copyright 1999, Texas Instruments Incorporated