This 20-bit bus-interface D-type latch is designed for 1.65-V to 3.6-V VCC operation.
The SN74ALVCH16841 features 3-state outputs designed specifically for driving highly capacitive or relatively low-impedance loads. This device is particularly suitable for implementing buffer registers, unidirectional bus drivers, and working registers.
The SN74ALVCH16841 can be used as two 10-bit latches or one 20-bit latch. The 20 latches are transparent D-type latches. The device has noninverting data (D) inputs and provides true data at its outputs. While the latch-enable (1LE or 2LE) input is high, the Q outputs of the corresponding 10-bit latch follow the D inputs. When LE is taken low, the Q outputs are latched at the levels set up at the D inputs.
A buffered output-enable (1OE\ or 2OE\) input can be used to place the outputs of the corresponding 10-bit latch in either a normal logic state (high or low logic levels) or the high-impedance state. In the high-impedance state, the outputs neither load nor drive the bus lines significantly.
OE\ does not affect the internal operation of the latches. Old data can be retained or new data can be entered while the outputs are in the high-impedance state.
To ensure the high-impedance state during power up or power down, 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.
Active bus-hold circuitry is provided to hold unused or floating data inputs at a valid logic level.
The SN74ALVCH16841 is characterized for operation from -40°C to 85°C.