FST3244 Datasheet, PDF (1/5 Pages) Fairchild Semiconductor – Octal Bus Switch

June 1997
Revised January 2005
FST3244
8-Bit Bus Switch
General Description
The Fairchild Switch FST3244 provides 8-bits of high-
speed CMOS TTL-compatible bus switching in a standard
’244 pin-out. The low on resistance of the switch allows
inputs to be connected to outputs without adding propaga-
tion delay or generating additional ground bounce noise.
The device is organized as two 4-bit switches with separate
OE inputs. When OE is LOW, the switch is ON and Port A
is connected to Port B. When OE is HIGH, 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:
Order Number Package Number
Package Description
FST3244WM
M20B
20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300" Wide
FST3244QSC
MQA20
20-Lead Quarter Size Outline Package (QSOP), JEDEC MO-137, 0.150" Wide
FST3244MTC
MTC20
20-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm Wide
FST3244MTCX_NL
(Note 1)
MTC20
Pb-Free 20-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153,
4.4mm Wide
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
Connection Diagram
Pin Descriptions
Pin Name
OE₁, OE₂
1A, 2A
1B, 2B
Description
Bus Switch Enable
Bus A
Bus B
© 2005 Fairchild Semiconductor Corporation DS500021
Truth Table
Inputs
OE₁
L
OE₂
L
L
H
H
L
H
H
Inputs/Outputs
1A, 1B
1A 1B
1A 1B
Z
Z
2A, 2B
2A 2B
Z
2A 2B
Z
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