SN74AHC74NSR集成电路（IC）的触发器规格书PDF中文资料

SN74AHC74NSR属于集成电路（IC）的触发器。由德州仪器制造生产的SN74AHC74NSR触发器触发器是能够存储单个逻辑状态或信息“位”的基本数字存储器件。这些器件至少有两个输入；一个或多个用于传递要存储的数据，另一个用于指示存储该数据的时间点。不同的触发器类型，例如 D（延迟）、SR（置位复位）和 JK，对提供给其输入的信号有不同的响应，可用于实现不同的逻辑功能。这些器件与锁存器的不同之处在于它们是边缘敏感器件，其保持的逻辑状态仅在接收到有效时钟信号时才会改变。

1 Features

• Operating range 2-V to 5.5-V VCC

• Latch-up performance exceeds 250 mA per JESD

17

• ESD protection exceeds JESD 22

– 2000-V Human-Body Model (A114-A)

– 200-V Machine Model (A115-A)

– 1000-V Charged-Device Model (C101)

2 Applications

• Convert a momentary switch to a toggle switch

• Hold a signal during controller reset

• Input slow edge-rate signals

• Operate in noisy environments

• Divide a clock signal by two

3 Description

The SNx4AHC74 dual positive-edge-triggered devices

are D-type flip-flops.

A low level at the preset (PRE) or clear (CLR) inputs

sets or resets the outputs, regardless of the levels

of the other inputs. When PRE and CLR are inactive

(high), data at the data (D) input meeting the setup

time requirements is transferred to the outputs on

the positive-going edge of the clock pulse. Clock

triggering occurs at a voltage level and is not directly

related to the rise time of the clock pulse. Following

the hold-time interval, data at the D input can be

changed without affecting the levels at the outputs.