These octal bus transceivers and registers are designed specifically for low-voltage (3.3-V) VCC operation, but with the capability to provide a TTL interface to a 5-V system environment.
The LVTH2952 devices consist of two 8-bit back-to-back registers that store data flowing in both directions between two bidirectional buses. Data on the A or B bus is stored in the registers on the low-to-high transition of 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 pullup or 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 circuitry disables 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.
|Part number||Order||Technology Family||VCC (Min) (V)||VCC (Max) (V)||Bits (#)||Voltage (Nom) (V)||F @ nom voltage (Max) (MHz)||ICC @ nom voltage (Max) (mA)||tpd @ nom Voltage (Max) (ns)||IOL (Max) (mA)||IOH (Max) (mA)||Operating temperature range (C)||Package Group|
||LVT||2.7||3.6||8||3.3||160||0.005||4.6||64||-32||-40 to 85||
SOIC | 24
TSSOP | 24