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
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MARKING
DIAGRAMS
20
1
SOIC−20
DW SUFFIX
CASE 751D
1
20
1
TSSOP−20
DT SUFFIX
CASE 948E
20
FST
3244
ALYW
1
FST3244
AWLYYWW
20
•
•
•
•
•
•
•
•
R
ON
t
4
W
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
0
2B
3
1A
1
2B
2
1A
2
2B
1
1A
3
2B
0
GND
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
V
CC
OE
2
1B
0
2A
3
1B
1
2A
2
1B
2
2A
1
1B
3
2A
0
20
1
QSOP−20
QS SUFFIX
CASE 492A
A
L, WL
Y
W, WW
=
=
=
=
20
FST3244
AWLYWW
1
Figure 1. 20−Lead Pinout
Assembly Location
Wafer Lot
Year
Work Week
PIN NAMES
TRUTH TABLE
Inputs
OE
1
L
L
H
H
OE
2
L
H
L
H
Inputs/Outputs
1A, 1B
1A = 1B
1A = 1B
Z
Z
2A, 2B
2A = 2B
Z
2A = 2B
Z
OE
1
, OE
2
1A, 2A
1B, 2B
Pin
Description
Bus Switch Enables
Bus A
Bus B
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 2 of this data sheet.
*For additional information on our Pb−Free strategy and soldering details, please
download the ON Semiconductor Soldering and Mounting Techniques
Reference Manual, SOLDERRM/D.
1
Publication Order Number:
74FST3244/D
©
Semiconductor Components Industries, LLC, 2006
June, 2006
−
Rev. 2
74FST3244
OE
1
1
1A
0
2
3
1B
0
1A
3
OE
3
5
10
6
1B
3
2A
0
9
8
2B
0
2A
3
12
11
2B
3
Figure 2. Logic Diagram
ORDERING INFORMATION
Device Order Number
74FST3244DW
74FST3244DWR2
74FST3244DT
74FST3244DTR2
74FST3244QS
74FST3244QSR
Package
SOIC−20
SOIC−20
TSSOP−20*
(Pb−Free)
TSSOP−20*
(Pb−Free)
QSOP−20
QSOP−20
Shipping
†
55 Units / Rail
1000 Units / Tape & Reel
75 Units / Rail
2500 Units / Tape & Reel
55 Units / Rail
2500 Units / Tape & Reel
†For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging
Specifications Brochure, BRD8011/D.
*This package is inherently Pb−Free.
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2
74FST3244
MAXIMUM RATINGS
Symbol
V
CC
V
I
V
O
I
IK
I
OK
I
O
I
CC
I
GND
T
STG
T
L
T
J
q
JA
DC Supply Voltage
DC Input Voltage
DC Output Voltage
DC Input Diode Current
DC Output Diode Current
DC Output Sink Current
DC Supply Current per Supply Pin
DC Ground Current per Ground Pin
Storage Temperature Range
Lead Temperature, 1 mm from Case for 10 Seconds
Junction Temperature Under Bias
Thermal Resistance (Note 1)
SOIC
TSSOP
QSOP
V
I
t
GND
V
O
t
GND
Parameter
Value
*0.5
to
)7.0
*0.5
to
)7.0
*0.5
to
)7.0
*50
*50
128
$100
$100
*65
to
)150
260
)150
96
128
200
Level 1
Oxygen Index: 28 to 34
Human Body Model (Note 2)
Machine Model (Note 3)
Above V
CC
and Below GND at 85_C (Note 4)
UL 94 V−0 @ 0.125 in
u2000
u200
$500
V
mA
Unit
V
V
V
mA
mA
mA
mA
mA
_C
_C
_C
_C/W
MSL
F
R
V
ESD
I
Latchup
Moisture Sensitivity
Flammability Rating
ESD Withstand Voltage
Latchup Performance
Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the
Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect
device reliability.
1. Measured with minimum pad spacing on an FR4 board, using 10 mm−by−1 inch, 2−ounce copper trace with no air flow.
2. Tested to EIA/JESD22−A114−A.
3. Tested to EIA/JESD22−A115−A.
4. Tested to EIA/JESD78.
RECOMMENDED OPERATING CONDITIONS
Symbol
V
CC
V
I
V
O
T
A
Dt/DV
Supply Voltage
Input Voltage
Output Voltage
Operating Free−Air Temperature
Input Transition Rise or Fall Rate
Switch Control Input
Switch I/O
Parameter
Operating, Data Retention Only
(Note )
(HIGH or LOW State)
Min
4.0
0
0
*40
0
0
Max
5.5
5.5
V
CC
)85
5
DC
Unit
V
V
V
_C
ns/V
5. Unused control inputs may not be left open. All control inputs must be tied to a high or low logic input voltage level.
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3
74FST3244
DC ELECTRICAL CHARACTERISTICS
V
CC
Symbol
V
IK
V
IH
V
IL
I
I
I
OZ
R
ON
Parameter
Clamp Diode Resistance
High−Level Input Voltage
Low−Level Input Voltage
Input Leakage Current
OFF−STATE Leakage Current
Switch On Resistance (Note 6)
0
v
V
IN
v
5.5 V
0
v
A, B
v
V
CC
V
IN
= 0 V, I
IN
= 64 mA
V
IN
= 0 V, I
IN
= 30 mA
V
IN
= 2.4 V, I
IN
= 15 mA
V
IN
= 2.4 V, I
IN
= 15 mA
I
CC
DI
CC
Quiescent Supply Current
Increase In I
CC
per Input
V
IN
= V
CC
or GND, I
OUT
= 0
One input at 3.4 V, Other inputs at V
CC
or GND
I
IN
=
*18mA
Conditions
(V)
4.5
4.0 to 5.5
4.0 to 5.5
5.5
5.5
4.5
4.5
4.5
4.0
5.5
5.5
4
4
8
11
2.0
0.8
$1.0
$1.0
7
7
15
20
3
2.5
mA
mA
T
A
=
*40_C
to
)85_C
Min
Typ*
Max
*1.2
Unit
V
V
V
mA
mA
W
*Typical values are at V
CC
= 5.0 V and T
A
= 25_C.
6. Measured by the voltage drop between A and B pins at the indicated current through the switch. On resistance is determined by the lower
of the voltages on the two (A or B) pins.
AC ELECTRICAL CHARACTERISTICS
Limits
T
A
=
*40_C
to
)85_C
V
CC
= 4.5 to 5.5 V
Symbol
t
PHL
,
t
PLH
t
PZH
,
t
PZL
t
PHZ
,
t
PLZ
Parameter
Prop Delay Bus to Bus
(Note 7)
Output Enable Time
Output Disable Time
Conditions
V
I
= OPEN
V
I
= 7 V for t
PZL
V
I
= OPEN for t
PZH
V
I
= 7 V for t
PLZ
V
I
= OPEN for t
PHZ
Figures
3 and 4
3 and 4
3 and 4
1.0
1.5
Min
Max
0.25
5.6
6.2
V
CC
= 4.0 V
Min
Max
0.25
6.1
5.6
Unit
ns
ns
ns
7. This parameter is guaranteed by design but is not tested. The bus switch contributes no propagation delay other than the RC delay of the
typical On resistance of the switch and the 50 pF load capacitance, when driven by an ideal voltage source (zero output impedance).
CAPACITANCE
(Note 8)
Symbol
C
IN
C
I/O
Parameter
Control Pin Input Capacitance
Input/Output Capacitance
V
CC
= 5.0 V
V
CC
, OE = 5.0 V
Conditions
Typ
3
5
Max
Unit
pF
pF
8. T
A
=
)25_C,
f = 1 MHz, Capacitance is characterized but not tested.
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4
74FST3244
AC Loading and Waveforms
V
I
FROM
OUTPUT
UNDER
TEST
500
W
C
L
*
500
W
NOTES:
1. Input driven by 50
W
source terminated in 50
W.
2. CL includes load and stray capacitance.
*C
L
= 50 pF
Figure 3. AC Test Circuit
t
f
= 2.5 nS
90 %
SWITCH
INPUT
1.5 V
10 %
t
PLH
1.5 V
90 %
1.5 V
t
f
= 2.5 nS
3.0 V
10 %
t
PLH
GND
V
OH
OUTPUT
1.5 V
V
OL
Figure 4. Propagation Delays
t
f
= 2.5 nS
t
f
= 2.5 nS
ENABLE
INPUT
90 %
1.5 V
10 %
t
PZL
OUTPUT
1.5 V
t
PZH
10 %
90 %
1.5 V
GND
t
PZL
3.0 V
V
OL
+ 0.3 V
V
OL
t
PHZL
V
OH
1.5 V
OUTPUT
V
OH
−
0.3 V
Figure 5. Enable/Disable Delays
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