The HD74LVC4245A has eight bus transceivers with three state outputs in a 24 pin package. When (DIR) is high, data flows from the A inputs to the B outputs, and when (DIR) is low, data flows from the B inputs to the A outputs. A and B bus are separated by making enable input (OE) high level. And this product has two terminals (VCCA, VCCB), VCCA (5V) is connected with control input and A bus side, VCCB (3.3V) connected with B bus side. VCCA and VCCB are isolated. This allows for translation from a 3.3 V to a 5 V environment, and vice versa. Low voltage and high-speed operation is suitable at the battery drive product (note type personal computer) and low power consumption extends the life of a battery for long time operation.