双D型触发器与预置和清除 Dual D-Type Flip-Flop with Preset and Clear
General Description
The MM74HCT74 utilizes advanced silicon-gate CMOS technology to achieve operation speeds similar to the equivalent LS-TTL part. It possesses the high noise immunity and low power consumption of standard CMOS integrated circuits, along with the ability to drive 10 LS-TTL loads.
This flip-flop has independent data, preset, clear, and clock inputs and Q and Q outputs. The logic level present at the data input is transferred to the output during the positive-going transition of the clock pulse. Preset and clear are independent of the clock and accomplished by a low level at the appropriate input.
The 74HCT logic family is functionally and pin-out compatible with the standard 74LS logic family. All inputs are protected from damage due to static discharge by internal diode clamps to VCC and ground.
Features
■ Typical propagation delay: 20ns
■ Low quiescent current: 40µA maximum 74HCT Series
■ Low input current: 1µA maximum
■ Fanout of 10 LS-TTL loads
■ Meta-stable hardened