Preliminary

© 2001 Fairchild Semiconductor Corporation

DS500563

www.fairchildsemi.com

February 2001

Revised August 2001

FSTD32450

Configurable 4-Bit to 40-Bit Bus Switch with

Selectable Level Shifting (Preliminary)

General Description

The Fairchild Universal Bus Switch FSTD32450 provides

4-bit, 5-bit, 8-bit, 10-bit, 16-bit, 20-bit...40-bit of high-speed

CMOS TTL-compatible bus switching. The low On Resis-

tance of the switch allows inputs to be connected to out-

puts without adding propagation delay or generating

additional ground bounce noise.

The FSTD32450 is designed to allow “customer” configura-

tion control of the enable connections. The device can be

organized as either a ten 4-bit, eight 5-bit, four 10-bit, two

20-bit or one 40-bit enabled bus switch. Also achievable

are 8-bit and 16-bit enabled configurations (see Functional

Description). The device’s bit configuration is controlled

the switch is OPEN.

Another key device feature is the addition of a level shifting

cuit allowing for level shifting between 5V inputs and 3.3V

outputs.

Features

s Voltage level shifting

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

s Packaged in plastic Fine-Pitch Ball Grid Array

(FBGA) (Preliminary)

Applications Note

used as static user configurable control pins. The AC per-

formance of these pins has not been characterized or

tested. Switching of these select pins during system opera-

tion may temporarily disrupt output logic states and/or

enable pin controls.

40-bit configuration can be achieved by connecting the

Ordering Code:

Note 1: BGA package available in Tape and Reel only.

UHC

 is a trademark of Fairchild Semiconductor Corporation.

Order Number

Package Number

Package Description

FSTD32450GX

(Note 1)

BGA114A

(Preliminary)

114-Ball Fine-Pitch Ball Grid Array (FBGA), JEDEC MO-205, 5.5mm Wide

[Tape and Reel]