This 18-bit universal bus transceiver is designed for 1.65-V to 3.6-V V_CC operation.

The SN74ALVCHR16601 combines D-type latches and D-type flip-flops to allow data flow in transparent, latched, clocked, and clock-enabled 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. The clock can be controlled by the clock-enable (CLKENAB\ and CLKENBA\) 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 data is stored in the latch/flip-flop on the low-to-high transition of CLKAB. When OEAB\ is low, the outputs are active. When OEAB\ is high, 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, CLKBA, and CLKENBA\.

The outputs include equivalent 26- series resistors to reduce overshoot and undershoot.

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

Active bus-hold circuitry holds unused or undriven inputs at a valid logic state. Use of pullup or pulldown resistors with the bus-hold circuitry is not recommended.