Fairchild Semiconductor FSTD162861 Datasheet

FSTD162861
20-Bit Bus Switch with Level Shifting

and 25

Ω Series Resistors in Outputs (Preliminary)

Preliminary

FSTD162861 20-Bit Bus Switch with Level Shifting and 25

June 2001
Revised June 2001

General Description

The Fairchild Switch FSTD162861 provides 20-bits of high­speed 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 b ounce noise. A diode to V

integrated into the circuit to allow for leve l shifting b etween
5V inputs and 3.3V outputs.

The device is organ ized as a 10-bit or 20-bit b us switch.
When OE

nected to Port 1B. When OE
to Port 2B. When OE
exists between the A an d B Ports. The FSTD16 2861 has

equivalent 25
noise, eliminating the ne ed for external terminating re sis­tors.

is LOW, the switch is ON and Port 1A is con-

1

Ω series resistors to reduce signal-reflect ion

is LOW, Port 2A is connected

2

is HIGH, a high imped ance state

X

has been

CC

Features

■ 25Ω switch connection between two ports

■ Minimal propagation delay through the switch

■ Low l

CC

■ Zero bounce in flow-through mode

■ Control inputs compatible with TTL level

■ TruTranslation

3.3V outputs

 voltage translation from 5.0V inp uts to

Ordering Code:

Order Number Package Number Package Description

FSTD162861MTD MTD48 48-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 6.1mm Wide

Devices also availab le in Tape and Reel. Specify by appending the suffix letter “X” to the o rdering code.

Ω

Series Resistors in Outputs (Preliminary)

TruTranslation is a trademark of F airc hild Semiconduct or Corporation.

© 2001 Fairchild Semiconductor Corporation DS500063 www.fairchildsemi.com

Logic Diagram Connection Diagram

FSTD162861

Truth Table Pin Descriptions

Inputs Inputs/Outputs

OE

LL1A
LH1A
HL Z 2A
HH Z Z

OE

1

2

1A, 1B 2A, 2B

= 1B 2A = 2B
= 1B Z

= 2B

Pin Name Description

, OE

OE

1

2

1A, 2A Bus A
1B, 2B Bus B

Preliminary

Bus Switch Enables

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