FSTD16861 20-Bit Bus Switch with Level Shifting
May 2001
Revised May 2001
FSTD16861
20-Bit Bus Switch with Level Shifting
General Description
The Fairchild Switch FSTD16861 provides 20-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. A diode to V
CC
has been
integrated into the circuit to allow for level shifting between
5V inputs and 3.3V outputs.
The device is organized as a 10-bit or 20-bit bus switch.
When OE
1
is LOW, the switch is ON and Port 1A is con-
nected to Port 1B. When OE
2
is LOW, Port 2A is connected
to Port 2B. When OE
X
is HIGH, a high impedance state
exists between the A and B Ports.
Features
s
4
鈩?/div>
switch connection between two ports.
s
Minimal propagation delay through the switch.
s
Low l
CC
.
s
Zero bounce in flow-through mode.
s
Control inputs compatible with TTL level.
s
TruTranslation
錚?/div>
voltage translation from 5.0V inputs to
3.3V outputs
Ordering Code:
Order Number
FSTD16861MTD
Package Number
MTD48
Package Description
48-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 6.1mm Wide
Devices also available in Tape and Reel. Specify by appending the suffix letter 鈥淴鈥?to the ordering code.
Connection Diagram
Logic Diagram
Truth Table
Inputs
Inputs/Outputs
OE
2
L
H
L
H
1A, 1B
1A
=
1B
1A
=
1B
Z
Z
2A, 2B
2A
=
2B
Z
2A
=
2B
Z
OE
1
L
Description
Bus Switch Enables
Bus A
Bus B
L
H
H
Pin Descriptions
Pin Name
OE
1
, OE
2
1A
n
, 2A
n
1B
n
, 2B
n
H
=
HIGH Voltage Level
L
=
LOW Voltage Level
Z
=
High Impedance
TruTranslation錚?is trademark of Fairchild Semiconductor Corporation.
漏 2001 Fairchild Semiconductor Corporation
DS500421
www.fairchildsemi.com
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