FSTD3125 4-Bit Bus Switch with Level Shifting
June 2001
Revised June 2001
FSTD3125
4-Bit Bus Switch with Level Shifting
General Description
The Fairchild Switch FSTD3125 provides four high-speed
CMOS TTL-compatible bus switches. The low On Resis-
tance of the switch allows inputs to be connected to out-
puts 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 four 1-bit switches with sepa-
rate 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
s
4
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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
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voltage translation from 5.0V inputs to
3.3V outputs
Ordering Code:
Order Number
FSTD3125M
FSTD3125QSC
FSTD3125MTC
Package Number
M14A
MQA16
MTC14
Package Description
14-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150" Narrow
16-Lead Quarter Size Outline Package (QSOP), JEDEC MO-137, 0.150" Wide
14-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 鈥淴鈥?to the ordering code.
Connection Diagrams
Pin Assignment for SOIC and TSSOP
Pin Descriptions
Pin Name
OE
1
, OE
2
, OE
3
, OE
4
1A, 2A, 3A, 4A
1B, 2B, 3B, 4B
NC
Description
Bus Switch Enables
Bus A
Bus B
Not Connected
Truth Table
Inputs
OE
Pin Assignment for QSOP
L
H
Inputs/Outputs
A, B
A
=
B
Z
TruTranslation铮?is a trademark of Fairchild Semiconductor Corporation.
漏 2001 Fairchild Semiconductor Corporation
DS500448
www.fairchildsemi.com
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