March 1997

Revised March 1999

© 1999 Fairchild Semiconductor Corporation

DS500004.prf

www.fairchildsemi.com

74VHCT245A

Octal Buffer/Line Driver with 3-STATE Outputs

General Description

The VHCT245A is an advanced high speed CMOS octal

bus transceiver fabricated with silicon gate CMOS technol-

ogy. It achieves high speed operation similar to equivalent

Bipolar Schottky TTL while maintaining the CMOS low

power dissipation. The VHCT245A is intended for bidirec-

tional asynchronous communication between data busses.

The direction of data transmission is determined by the

level of the T/R input. The enable input can be used to dis-

able the device so that the busses are effectively isolated.

Protection circuits ensure that 0V to 7V can be applied to

the input and output (Note 1) pins without regard to the

supply voltage. These circuits prevent device destruction

due to mismatched supply and input/output voltages. This

device can be used to interface 5V to 3V systems and two

supply systems such as battery back up.

Note 1: Outputs in OFF-State

Features

s Power Down Protection on Inputs and Outputs

s Pin and Function Compatible with 74HCT245

Ordering Code:

Surface mount packages are also available on Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.

Logic Symbol

IEEE/IEC

Pin Descriptions

Connection Diagram

Truth Table

H

= HIGH Voltage Level

L

= LOW Voltage Level

X

= Immaterial

Order Number

Package Number

Package Description

74VHCT245AM

M20B

20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide

74VHCT245ASJ

M20D

20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide

74VHCT245AMTC

MTC20

20-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm Wide

74VHCT245AN

N20A

20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide

Pin Names

Description

OE

Output Enable Input

T/R

Transmit/Receive Input

Side A Inputs or 3-STATE Outputs

Side B Inputs or 3-STATE Outputs

Inputs

Outputs

OE

T/R

L

L

Bus B Data to Bus A

L

H

Bus A Data to Bus B

H

X

HIGH-Z State