SN74GTLPH306DGVR

8位LVTTL至GTLP总线收发器 8-BIT LVTTL-TO-GTLP BUS TRANSCEIVER

The SN74GTLPH306 is a medium-drive, 8-bit bus transceiver that provides LVTTL-to-GTLP and GTLP-to-LVTTL signal-level translation. 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 LVTTL or TTL backplane operation is a direct result of GTLP"s reduced output swing <1 V, reduced input threshold levels, improved differential input, OEC™ circuitry, and -OPC™ circuitry. Improved GTLP OEC and TI-OPC circuits minimize bus-settling time and have been designed and tested using several backplane models. The medium drive allows incident-wave switching in heavily loaded backplanes with equivalent load impedance down to 19 .

GTLP is the Texas Instruments TI™ derivative of the Gunning Transceiver Logic GTL JEDEC standard JESD 8-3. The ac specification of the SN74GTLPH306 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. VREF is the B-port differential input reference voltage.

This device is fully specified for hot-insertion applications using Ioff and power-up 3-state. The Ioff circuitry disables the outputs, preventing damaging current backflow through the device when it is powered down. The power-up 3-state circuitry places the outputs in the high-impedance state during power up and power down, which prevents driver conflict.

This GTLP device features TI-OPC circuitry, which actively limits overshoot caused by improperly terminated backplanes, unevenly distributed cards, or empty slots during low-to-high signal transitions. This improves signal integrity, which allows adequate noise margin to be maintained at higher frequencies.

Active bus-hold circuitry holds unused or undriven LVTTL data inputs at a valid logic state. Use of pullup or pulldown resistors with the bus-hold circuitry is not recommended.

When VCC is between 0 and 1.5 V, the device is in the high-impedance state during power up or power down. However, to ensure the high-impedance state above 1.5 V, the output-enable OE\\\\ input should be tied to VCC through a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver. View datasheet View product folder