CD74HCT646集成电路（IC）的缓冲器驱动器接收器收发器规格书PDF中文资料

CD74HCT646属于集成电路（IC）的缓冲器驱动器接收器收发器。由美国德州仪器公司制造生产的CD74HCT646缓冲器，驱动器，接收器，收发器逻辑缓冲器、驱动器、接收器和收发器允许隔离对某个电路的逻辑信号的访问，以用于另一电路。缓冲器将其输入信号（不变或反相）传递到其输出，并可能用于清除弱信号或驱动负载。在布尔逻辑仿真器中，缓冲器主要用于增加传播延迟。逻辑接收器和收发器允许在数据总线之间进行隔离通信。

2-V to 6-V VCC Operation (CD54HC646)

4.5-V to 5.5-V VCC Operation (CD74HCT646)

Wide Operating Temperature Range of

–55°C to 125°C

Balanced Propagation Delays and

Transition Times

Standard Outputs Drive Up To 15 LS-TTL

Loads

Significant Power Reduction Compared to

LS-TTL Logic ICs

Inputs Are TTL-Voltage Compatible

(CD74HCT646)

Independent Registers for A and B Buses

Multiplexed Real-Time and Stored Data

True Data Paths

description/ordering information

The CD54HC646 and CD74HCT646 consist of bus-transceiver circuits with 3-state outputs, D-type flip-flops,

and control circuitry arranged for multiplexed transmission of data directly from the input bus or from the internal

registers. Data on the A or B bus is clocked into the registers on the low-to-high transition of the appropriate

clock (CLKAB or CLKBA) input. Figure 1 illustrates the four fundamental bus-management functions that can

be performed with these devices.

Output-enable (OE) and direction-control (DIR) inputs control the transceiver functions. In the transceiver

mode, data present at the high-impedance port can be stored in either or both registers.

The select-control (SAB and SBA) inputs can multiplex stored and real-time (transparent mode) data. DIR

determines which bus receives data when OE is active (low). In the isolation mode (OE high), A data can be

stored in one register and/or B data can be stored in the other register.

When an output function is disabled, the input function still is enabled and can be used to store data. Only one

of the two buses, A or B, can be driven at a time.

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.