Rev.2.00, Jul.16.2004, page 1 of 7

HD74BC640A

Octal Bus Transceivers With 3 State Outputs

REJ03D0290–0200Z

(Previous ADE-205-026 (Z))

Rev.2.00

Jul.16.2004

Description

The HD74BC640A provides high drivability and operation equal to or better than high speed bipolar standard logic IC

by using Bi-CMOS process. The device features low power dissipation that is about 1/5 of high speed bipolar logic IC.

When the frequency is 10 MHz. The device has eight bus transceivers with three state outputs in a 20 pin package.

Each device has an active low enable input (

G) and a direction control input, DiR. When DiR is high, data flows from

the A inputs to the B outputs. When DiR is high, data flows from the B inputs to the A outputs. When enable inputs

(

G) is high, disables both A and B ports by placing then in a high impedance.

Features

• Input/Output are at high impedance state when power supply is off.

• Input pins can be open, when not used, owing to built in input pull up circuit.

• Input is TTL level.

• Wide operating temperature range

Ta = –40 to +85°C.

• Ordering Information

Part Name

Package Type

Package Code

Package

Abbreviation

Taping Abbreviation

(Quantity)

HD74BC640AFPEL

SOP-20 pin (JEITA) FP-20DAV

FP

EL (2,000 pcs/reel)

Function Table

Control Inputs

G

G

G

G

DIR

Operation

LL

B data to A bus

LH

A data to B bus

H

X

Isolation

H :

High level

L

:

Low level

X :

Immaterial