The ABT16500 18-bit universal bus transceiver combines D-type latches and D-type flip-flops to allow data flow in transparent, latched, and clocked modes.

Data flow in each direction is controlled by output-enable (OEAB and OEBA#), latch-enable (LEAB and LEBA), and clock (CLKAB# and CLKBA#) inputs. For A-to-B data flow, the device operates in the transparent mode when LEAB is HIGH. When LEAB is LOW, the A data is latched if CLKAB# is held at a HIGH or LOW logic level. If LEAB is LOW, the A bus data is stored in the latch/flip-flop on the HIGH-to-LOW transition of CLKAB#. Output-enable OEAB is active-high. When OEAB is HIGH, the outputs are active. When OEAB is LOW, the outputs are in the high-impedance state.

Data flow for B to A is similar to that of A to B but uses OEBA#, LEBA, and CLKBA#. The output enables are complementary (OEAB is active HIGH and OEBA# is active LOW).

To ensure the high-impedance state during power up or power down, OE should be tied to GND through a pulldown resistor; the minimum value of the resistor is determined by the current-sourcing capability of the driver.

• Combines D-Type latches and D-Type flip-flops for operation in transparent, latched, or clocked mode
• Flow-through architecture optimizes PCB layout
• Guaranteed latch-up protection
• High impedance glitch free bus loading during entire power up and power down cycle
• Non-destructive hot insertion capability