© 2005 Fairchild Semiconductor Corporation

DS500019

www.fairchildsemi.com

June 1997

Revised March 2005

FST3345

8-Bit Bus Switch

General Description

The Fairchild Switch FST3345 provides 8-bits of high-

speed CMOS TTL-compatible bus switching. The low on

resistance of the switch allows inputs to be connected to

outputs without adding propagation delay or generating

additional ground bounce noise.

The device is organized as an 8-bit switch bank with dual

output enable inputs (OE and OE). When OE is LOW or

OE is HIGH, the switch is ON and Port A is connected to

Port B. When OE is HIGH and OE is LOW, the switch is

OPEN and a high-impedance state exists between the two

ports.

Features

s 4

: switch connection between two ports.

s Minimal propagation delay through the switch.

s Zero bounce in flow-through mode.

s Control inputs compatible with TTL level.

Ordering Code:

Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.

Note 1: “_NL” indicates Pb-Free package (per JEDEC J-STD-020B). Device available in Tape and Reel only.

Logic Diagram

Pin Descriptions

Connection Diagram

Truth Table

Order Number

Package

Package Description

Number

FST3345WM

M20B

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

FST3345QSC

MQA20

20-Lead Quarter Size Outline Package (QSOP), JEDEC MO-137, 0.150" Wide

FST3345MTC

MTC20

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

FST3345MTCX_NL

(Note 1)

MTC20

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

Wide

Pin Name

Description

OE, OE

Bus Switch Enables

ABus A

BBus B

Inputs

Function

OE

OE

X

L

Connect

H

X

Connect

L

H

Disconnect