M74HC640 - ST Microelectronics

M74HC640 OCTAL BUS TRANSCEIVER

The M54/74HC245, HC640 and HC643 utilise silicon gate C2MOS technology to achive operating speeds equivalent to LSTTL devices. Along with the low power dissipation and high noise 2 immunity of standards C MOS integrated circuit, it possesses the capability to drive 15 LSTTL loads. These IC’s are intended for two-way asynchronous communication between data bu.

Features

e intended for two-way asynchronous communication between data buses, and the direction of data trasmission is determined by DIR input. The enable input (G) can be used to disable the device so that the buses are effectively isolated. PIN CONNECTION (top view) HC245 HC640 HC643 All input are equipped with protection circuits against static discharge and transient discharge and transient excess voltage. IT IS PROHIBITED TO APPLY A SIGNAL TO A BUS TERMINAL WHEN IT IS IN OUTPUT MODE AND WHEN A BUS THERMINAL IS FLOATING (HIGH IMPEDANCE STATE), IT IS REQUESTED TO FIX THE INPUT LEVEL BY MEANS OF EX.