 Semiconductor Components Industries, LLC, 2005
January, 2005 − Rev. 1
1 Publication Order Number:
74FST3244/D
74FST3244
8-Bit Bus Switch
The ON Semiconductor 74FST3244 is an 8−bit, high performance
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.
The device consists of two 4−bit switches with separate
Output/Enable (OE) pins. Port A is connected to Port B when OE is
low. If OE is high, the switch is high Z.
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 QS3244, FST3244, CBT3244
• All Popular Packages: QSOP−20, TSSOP−20, SOIC−20
• All Devices in Package TSSOP are Inherently Pb−Free*
OE
1
1A
1
2B
1
1A
2
2B
2
2B
3
1A
0
V
CC
2A
3
1B
2
2A
2
1B
1
1B
0
OE
2
1
2
3
4
5
6
7
20
19
18
17
16
15
14
Figure 1. 20−Lead Pinout
1A
3
8
2B
0
9
GND 10
2A
1
13
1B
3
12
2A
0
11
OE
1
L
Inputs
L
H
OE
2
L
H
L
HH
1A, 1B
1A = 1B
1A = 1B
Inputs/Outputs
Z
Z
2A, 2B
2A = 2B
Z
2A = 2B
Z
TRUTH TABLE
*For additional information on our Pb−Free strategy and soldering details, please
download the ON Semiconductor Soldering and Mounting Techniques
Reference Manual, SOLDERRM/D.
Description
PIN NAMES
OE
1
, OE
2
1A, 2A
TSSOP−20
DT SUFFIX
CASE 948E
QSOP−20
QS SUFFIX
CASE 492A
SOIC−20
DW SUFFIX
CASE 751D
MARKING
DIAGRAMS
Pin
Bus Switch Enables
Bus A
1B, 2B Bus B
20
1
FST3244
AWLYYWW
1
20
20
1
FST
3244
ALYW
A = Assembly Location
L, WL = Wafer Lot
Y = Year
W, WW = Work Week
1
20
FST3244
AWLYWW
20
1
See detailed ordering and shipping information in the package
dimensions section on page 2 of this data sheet.
ORDERING INFORMATION
20
1
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