© 2001 Fairchild Semiconductor Corporation

DS500432

www.fairchildsemi.com

April 2001

Revised April 2001

FSTU16245

16-Bit Bus Switch with

−2V Undershoot Protection

General Description

The Fairchild Switch FSTU16245 provides 16-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 a 16-bit switch. There are two

8-bit switches with separate output enable inputs. When

OE is LOW, the switch is ON and Port a is connected to

Port B. When OE is HIGH, the switch is OFF and a high

impedance state exists between the A and B Ports. The A

and B Ports are protected against undershoot to support

an extended range to 2.0V below ground. Fairchild’s inte-

grated Undershoot Hardened Circuit (UHC

) senses

undershoot at the I/O and responds by preventing voltage

differentials from developing and turning the switch on.

When OE is HIGH, the switch is OPEN and a high-imped-

ance state exists between the two ports.

Features

I Undershoot hardened to

−2V (A and B Ports)

I 4

Ω switch connection between two ports.

I Minimal propagation delay through the switch.

I Zero bounce in flow-through mode.

I Control inputs compatible with TTL level.

I See Application Note AN-5008 for details

Ordering Code:

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

Connection Diagram

Pin Descriptions

UHC

 is a trademark of Fairchild Semiconductor Corporation.

Order Number

Package Number

Package Description

FSTU16245MTD

MTD48

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

Pin Name

Description

Output Enable Input (Active LOW)

Bus A

Bus B

NC

No Internal Connection