SN74LVTH2952NSRE4

SN74LVTH2952NSRE4 description/ordering information

These octal bus transceivers and registers are designed specifically for low-voltage (3.3-V) VCC operation, butwith the capability to provide a TTL interface to a 5-V system environment.ORDERING INFORMATION

SN74LVTH2952NSRE4 description/ordering information

The ’LVTH2952 devices consist of two 8-bit back-to-back registers that store data flowing in both directionsbetween two bidirectional buses. Data on the A or B bus is stored in the registers on the low-to-high transitionof the clock (CLKAB or CLKBA) input, provided that the clock-enable (CLKENAB or CLKENBA) input is low.Taking the output-enable (OEAB or OEBA) input low accesses the data on either port.Active bus-hold circuitry is provided to hold unused or floating data inputs at a valid logic level. Use of pullupor pulldown resistors with the bus-hold circuitry is not recommended.When VCC is between 0 and 1.5 V, the devices are in the high-impedance state during power up or power down.However, to ensure the high-impedance state above 1.5 V, OE 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.These devices are fully specified for hot-insertion applications using Ioff and power-up 3-state. The Ioff circuitrydisables the outputs, preventing damaging current backflow through the devices when they are 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.