The SN74GTLP1394 is a high-drive, 2-bit, 3-wire bus transceiver that provides LVTTL-to-GTLP and GTLP-to-LVTTL signal-level translation. It allows for transparent and inverted transparent modes of data transfer with separate LVTTL input and LVTTL output pins, which provides a feedback path for control and diagnostics monitoring. The device provides a high-speed interface between cards operating at LVTTL logic levels and a backplane operating at GTLP signal levels, and is especially designed to work with the Texas Instruments 1394 backplane physical-layer controllers. High-speed (about three times faster than standard LVTTL or TTL) backplane operation is a direct result of GTLP reduced output swing (<1 V), reduced input threshold levels, improved differential input, OEC™ circuitry, and TI-OPC™ circuitry. Improved GTLP OEC and TI-OPC circuitry minimizes 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 TI derivative of the Gunning Transceiver Logic (GTL) JEDEC standard JESD 8-3. The ac specification of the SN74GTLP1394 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.

Normally, the B port operates at GTLP signal levels. The A-port and control inputs operate at LVTTL logic levels, but are 5-V tolerant and are compatible with TTL and 5-V CMOS inputs. VREFis the B port differential input reference voltage.Read more