Octal bus transceiver with hot insertion and bus-hold capability

The 74LVT245BB octal transceiver from Diodes Incorporated enables asynchronous communication between data buses. A control pin determines data flow direction, while disabling the tri-state outputs allows the buses to be completely isolated. Once reserved primarily for computer applications, data buses are now commonplace in TVs, set-top boxes, base stations and a myriad of other data communication devices, providing a broad market for transceiver circuits. The 74LVT245BB adds a partial power-down capability to the normal asynchronous communication between data buses. This disables the outputs and prevents damaging current backflow when the device is powered down. It also withstands hot insertion by maintaining the tri-state output during power up. Schmitt trigger action inputs also include a bus-hold feature so no resistors are required on unused inputs. Combined with a latch-up immunity of better than 500mA, these transceivers enable board designs that can be hot-swapped in applications like computer servers and cell phone base stations without the need to turn equipment off. Operation of the 74LVT245BB is specified for a supply voltage range of 2.7V to 3.6V and inputs can be driven at 3.3V or 5V, allowing for mixed-logic voltage applications. Outputs can sink 64mA or source 32mA and have leakage current of <125µA when forced to 5.5V. With a 2.7ns (typical) propagation time, a drive capability suitable for large bus architectures, and the ability to power down to avoid loading the data bus, the 74LVT245BB delivers gains in power performance ratio, reliability and cost. The devices are available in single-reel quantities of 2500 pieces in TSSOP-20 and the smaller QFN-20 package.