© 2005 Fairchild Semiconductor Corporation

DS500012

www.fairchildsemi.com

June 1997

Revised April 2005

74VHCT540A

Octal Buffer/Line Driver with 3-STATE Outputs

General Description

The VHCT540A is an advanced high-speed CMOS device

fabricated with silicon gate CMOS technology. It achieves

the high-speed operation similar to equivalent Bipolar

Schottky TTL while maintaining the CMOS low power dissi-

pation.

The VHCT540A is an octal buffer/line driver designed to be

employed as memory and address drivers, clock drivers

and bus oriented transmitter/receivers.

This device is similar in function to the VHCT240A while

providing flow-through architecture (inputs on opposite side

from outputs). This pinout arrangement makes this device

especially useful as an output port for microprocessors,

allowing ease of layout and greater PC board density.

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

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

supply voltage. This device can be used to interface 3V to

5V systems and two supply systems such as battery

backup. This circuit prevents device destruction due to mis-

matched supply and input voltages.

Note 1: Outputs in OFF-STATE

Features

s Power down protection is provided on all inputs and

outputs

s Pin and function compatible with 74HCT540

Ordering Code:

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

Pb-Free package per JEDEC J-STD-020B.

Logic Symbol

IEEE/IEC

Pin Descriptions

Connection Diagram

Truth Table

H

HIGH Voltage Level

X

Immaterial

L

LOW Voltage Level

Z

High Impedance

Order Number

Package Number

Package Dissipation

74VHCT540AM

M20B

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

74VHCT540ASJ

M20D

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

74VHCT540AMTC

MTC20

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

74VHCT540AN

N20A

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

Pin Names

Description

3-STATE Output Enable Inputs

Inputs

3-STATE Outputs

Inputs

Outputs

I

LL

H

L

HX

X

Z

XH

X

Z

LLL

H