 Semiconductor Components Industries, LLC, 2005
January, 2005 − Rev. 2
1 Publication Order Number:
74FST3257/D
74FST3257
Quad 2:1 Multiplexer/
Demultiplexer Bus Switch
The ON Semiconductor 74FST3257 is a quad 2:1, high performance
multiplexer/demultiplexer bus switch. The device is CMOS TTL
compatible when operating between 4 and 5.5 Volts. The device
exhibits extremely low R
ON
and adds nearly zero propagation delay.
The device adds no noise or ground bounce to the system.
Features
• R
ON
4 Typical
• Less Than 0.25 ns−Max Delay Through Switch
• Nearly Zero Standby Current
• No Circuit Bounce
• Control Inputs are TTL/CMOS Compatible
• Pin−For−Pin Compatible With QS3257, FST3257, CBT3257
• All Popular Packages: QSOP−16, TSSOP−16, SOIC−16
• All Devices in Package TSSOP are Inherently Pb−Free*
1A
2A
2B
2
2B
1
1B
2
S V
CC
OE
GND 3A
1
2
3
4
5
6
7
16
15
14
13
12
11
10
89
Figure 1. 16−Lead Pinout
Figure 2. Truth Table
1B
1
4B
1
4B
2
4A
3B
2
X
L
H
S Function
H
L
L
OE
Disconnect
A = B
1
A = B
2
3B
1
*For additional information on our Pb−Free strategy and soldering details, please
download the ON Semiconductor Soldering and Mounting Techniques
Reference Manual, SOLDERRM/D.
A = Assembly Location
L, WL = Wafer Lot
Y = Year
W, WW = Work Week
TSSOP−16
DT SUFFIX
CASE 948F
16
1
QSOP−16
QS SUFFIX
CASE 492
SOIC−16
D SUFFIX
CASE 751B
16
1
1
16
FST3257
AWLYWW
MARKING
DIAGRAMS
16
1
16
1
1
16
FST
3257
ALYW
S3257
ALYW
Description
PIN NAMES
OE
1
, OE
2
S
0
, S
1
Pin
Bus Switch Enables
Select Inputs
A Bus A
B
1
, B
2
, B
3
, B
4
Bus B
See detailed ordering and shipping information in the package
dimensions section on page 2 of this data sheet.
ORDERING INFORMATION
http://onsemi.com