© 1999 Fairchild Semiconductor Corporation

DS500038

www.fairchildsemi.com

July 1997

Revised December 1999

FST16212

24-Bit Bus Exchange Switch

General Description

The Fairchild Switch FST16212 provides 24-bits of high-

speed CMOS TTL-compatible bus switching or exchang-

ing. 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 operates as a 24-bit bus switch or a 12-bit bus

exchanger, which allows data exchange between the four

signal ports via the data-select terminals.

Features

s 4

Ω 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.

Logic Diagram

Truth Table

Connection Diagram

Pin Descriptions

Order Number

Package Number

Package Description

FST16212MEA

MS56A

56-Lead Shrink Small Outline Package (SSOP), JEDEC MO-118, 0.300 Wide

FST16212MTD

MTD56

56-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 6.1mm Wide

S2

S1

S0

Function

L

L

L

Z

Z

Disconnect

LL

H

LH

L

LH

H

Z

HL

L

Z

H

L

H

Z

Z

Disconnect

HH

L

HH

H

Pin Name

Description

S2, S1, S0

Data-select inputs

Bus A

Bus B