74FST3245
8−Bit Bus Switch
The ON Semiconductor 74FST3245 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 an 8−bit switch. Port A is connected to Port B
when OE is low. If OE is high, the switch is high Z.
Features
20
20
1
SOIC−20
DW SUFFIX
CASE 751D
FST3245
AWLYYWW
1
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MARKING
DIAGRAMS
•
•
•
•
•
•
•
•
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 QS3245, FST3245, CBT3245
All Popular Packages: QSOP−20, TSSOP−20, SOIC−20
All Devices in Package TSSOP are Inherently Pb−Free*
NC
A
0
A
1
A
2
A
3
A
4
A
5
A
6
A
7
GND
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
V
CC
OE
B
0
B
1
B
2
B
3
B
4
B
5
B
6
B
7
20
1
TSSOP−20
DT SUFFIX
CASE 948E
20
FST
3245
ALYW
1
20
1
QSOP−20
QS SUFFIX
CASE 492A
FST3245
AWLYWW
1
20
Figure 1. 20−Lead Pinout
OE
19
A
0
2
18
B
0
A
L, WL
Y
W, WW
=
=
=
=
Assembly Location
Wafer Lot
Year
Work Week
PIN NAMES
A
7
9
11
Pin
B
7
OE
1
, OE
2
1A, 2A
1B, 2B
Description
Bus Switch Enables
Bus A
Bus B
Figure 2. Logic Diagram
TRUTH TABLE
Input OE
L
H
Function
Connect
Disconnect
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 3 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.
©
Semiconductor Components Industries, LLC, 2006
June, 2006
−
Rev. 2
1
Publication Order Number:
74FST3245/D
74FST3245
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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2
74FST3245
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.
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
1.5
1.5
Min
Max
0.25
5.9
6.0
V
CC
= 4.0 V
Min
Max
0.25
6.4
5.7
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.
ORDERING INFORMATION
Device Order Number
74FST3245DW
74FST3245DWR2
74FST3245DT
74FST3245DTR2
74FST3245QS
74FST3245QSR
Package
SOIC−20
SOIC−20
TSSOP−20*
(Pb−Free)
TSSOP−20*
(Pb−Free)
QSOP−20
QSOP−20
Shipping
†
38 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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3
74FST3245
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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4
74FST3245
PACKAGE DIMENSIONS
SOIC−20
DW SUFFIX
CASE 751D−05
ISSUE G
D
NOTES:
1. DIMENSIONS ARE IN MILLIMETERS.
2. INTERPRET DIMENSIONS AND TOLERANCES
PER ASME Y14.5M, 1994.
3. DIMENSIONS D AND E DO NOT INCLUDE MOLD
PROTRUSION.
4. MAXIMUM MOLD PROTRUSION 0.15 PER SIDE.
5. DIMENSION B DOES NOT INCLUDE DAMBAR
PROTRUSION. ALLOWABLE PROTRUSION
SHALL BE 0.13 TOTAL IN EXCESS OF B
DIMENSION AT MAXIMUM MATERIAL
CONDITION.
DIM
A
A1
B
C
D
E
e
H
h
L
q
MILLIMETERS
MIN
MAX
2.35
2.65
0.10
0.25
0.35
0.49
0.23
0.32
12.65
12.95
7.40
7.60
1.27 BSC
10.05
10.55
0.25
0.75
0.50
0.90
0
_
7
_
A
11
X 45
_
q
H
M
B
M
20
10X
0.25
E
1
10
20X
B
0.25
M
B
T A
S
B
S
A
e
SEATING
PLANE
h
18X
A1
T
C
TSSOP−20
DT SUFFIX
CASE 948E−02
ISSUE B
20X
K
REF
M
L
0.15 (0.006) T U
S
0.10 (0.004)
T U
S
V
S
L
B
PIN 1
IDENT
1
10
J J1
−U−
N
0.15 (0.006) T U
S
A
−V−
N
F
C
D
0.100 (0.004)
−T−
SEATING
PLANE
G
H
DETAIL E
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5
ÍÍÍÍ
ÍÍÍÍ
ÍÍÍÍ
SECTION N−N
M
DETAIL E
2X
L/2
20
11
K
K1
0.25 (0.010)
NOTES:
1. DIMENSIONING AND TOLERANCING
PER ANSI Y14.5M, 1982.
2. CONTROLLING DIMENSION:
MILLIMETER.
3. DIMENSION A DOES NOT INCLUDE
MOLD FLASH, PROTRUSIONS OR GATE
BURRS. MOLD FLASH OR GATE BURRS
SHALL NOT EXCEED 0.15 (0.006) PER
SIDE.
4. DIMENSION B DOES NOT INCLUDE
INTERLEAD FLASH OR PROTRUSION.
INTERLEAD FLASH OR PROTRUSION
SHALL NOT EXCEED 0.25 (0.010) PER
SIDE.
5. DIMENSION K DOES NOT INCLUDE
DAMBAR PROTRUSION. ALLOWABLE
DAMBAR PROTRUSION SHALL BE 0.08
(0.003) TOTAL IN EXCESS OF THE K
DIMENSION AT MAXIMUM MATERIAL
CONDITION.
6. TERMINAL NUMBERS ARE SHOWN
FOR REFERENCE ONLY.
7. DIMENSION A AND B ARE TO BE
DETERMINED AT DATUM PLANE
−W−.
MILLIMETERS
MIN
MAX
6.40
6.60
4.30
4.50
−−−
1.20
0.05
0.15
0.50
0.75
0.65 BSC
0.27
0.37
0.09
0.20
0.09
0.16
0.19
0.30
0.19
0.25
6.40 BSC
0
_
8
_
INCHES
MIN
MAX
0.252
0.260
0.169
0.177
−−− 0.047
0.002
0.006
0.020
0.030
0.026 BSC
0.011
0.015
0.004
0.008
0.004
0.006
0.007
0.012
0.007
0.010
0.252 BSC
0
_
8
_
−W−
DIM
A
B
C
D
F
G
H
J
J1
K
K1
L
M
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