SN54LV573A

The SN54LV573A devices are octal transparent D-type latches designed for 2-V to 5.5-V VCC operation. These devices feature 3-state outputs designed specifically for driving highly capacitive or relatively low-impedance loads. SN54LV573A is particularly suitable for implementing buffer registers, I/O ports, bidirectional bus drivers, and working registers. While the latch-enable (LE) input is high, the Q outputs follow the data (D) inputs. When LE is taken low, the Q outputs are latched at the logic levels set up at the D inputs.

A buffered output-enable (OE) input of SN54LV573A can be used to place the eight outputs in either a normal logic state (high or low logic levels) or high-impedance state. In the high-impedance state, the outputs neither load nor drive the bus lines significantly. The high-impedance state and increased drive provide the capability to drive bus lines without need for interface or pullup components. OE does not affect the internal operations of the latches. Old data of SN54LV573A 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. The SN54LV573A is characterized for operation over the full military temperature range of 55°C to 125°C. The SN74LV573A is characterized for operation from 40°C to 85°C.