M74HCT640 is a replacement for the 74HCT640 and is manufactured using silicon gate C2MOS technology. It has high speed and low power characteristics. This device is intended for two-way asynchronous communication between data buses. The DIR input determines the direction of data transmission. The G input can be used to disable the device so that the buses are effectively isolated. All inputs are equipped with protection circuits against static discharge and transient excess voltage.