描述 Description

These 8-bit flip-flops feature 3-state outputs designed specifically for driving highly capacitive or relatively low-impedance loads. They are particularly suitable for implementing buffer registers, I/O ports, bidirectional bus drivers, and working registers.

The eight flip-flops of the ?HCT374 devices are edge-triggered D-type flip-flops. On the positive transition of the clock (CLK) input, the Q outputs are set to the logic levels that were set up at the data (D) inputs.

An output-enable (OE)\\ input places the eight outputs 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. The high-impedance state and increased drive provide the capability to drive bus lines without interface or pullup components.

(OE)\\ does not affect the internal operations of the flip-flops. Old data can be retained or new data can be entered while the outputs are in the high-impedance state.

特性 Features

? Operating Voltage Range of 4.5 V to 5.5 V
? High-Current 3-State True Outputs Can Drive Up To 15 LSTTL Loads
? Low Power Consumption, 80-μA Max ICC
? Typical tpd = 22 ns
? ±6-mA Output Drive at 5 V
? Low Input Current of 1 μA Max
? Inputs Are TTL-Voltage Compatible
? Eight D-Type Flip-Flops in a Single Package
? Full Parallel Access for Loading