
Fairchild Semiconductor
General Description
The LVTH646 consists of registered bus transceiver circuits, D-type flip-flops, and control circuitry providing multiplexed transmission of data directly from the input bus or from the internal storage registers. Data on the A or B bus will be loaded into the respective registers on the LOW-to-HIGH transition of the appropriate clock pin (CPAB or CPBA). (See Functional Description)
The LVTH646 data inputs include bushold, eliminating the need for external pull-up resistors to hold unused inputs.
The bus transceivers are designed for low-voltage (3.3V) VCC applications, but with the capability to provide a TTL interface to a 5V environment. The LVTH646 is fabricated with an advanced BiCMOS technology to achieve high speed operation similar to 5V ABT while maintaining low power dissipation.
FEATUREs
■ Input and output interface capability to systems at 5V VCC
■ Bushold data inputs eliminate the need for external
pull-up resistors to hold unused inputs
■ Live insertion/extraction permitted
■ Power Up/Down high impedance provides glitch-free bus loading
■ Outputs source/sink −32 mA/+64 mA
■ Functionally compatible with the 74 series 646
■ Latch-up performance exceeds 500 mA