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© 2005 Fairchild Semiconductor Corporation DS500019 www.fairchildsemi.com
June 1997
Revised March 2005
FST3345 8-Bit Bus Switch
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
■ 4
:
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.
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
