ON Semiconductor 74FST3245QSR, 74FST3245QS, 74FST3245DWR2, 74FST3245DW, 74FST3245DTR2 Datasheet

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 RON 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

• R

• 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

is low. If OE is high, the switch is high Z.

 4  Typical

ON

20

SO–20
DW SUFFIX
CASE 751D

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20

1

1

MARKING

DIAGRAMS

FST3245

AWLYYWW

1

NC

2

A

0

3

A

1

4

A

2

5

A

3

6

A

4

7

A

5

8

A

6

9

A

7

GND

10

Figure 1. 20–Lead Pinout

19

OE

2

A

0

9

A

7

Figure 2. Logic Diagram

20
19
18
17
16
15
14
13
12
11

V
OE
B
B
B
B
B
B

B
B

CC

0
1
2
3
4
5
6
7

18

11

20

1

TSSOP–20
DT SUFFIX

CASE 948E

20

1

QSOP–20
QS SUFFIX
CASE 492A

A = Assembly Location
L, WL = Wafer Lot
Y = Year

B

0

W, WW = Work Week

20

FST

3245

ALYW

1

20

FST3245

AWLYWW

1

PIN NAMES

Pin

OE1, OE

B

7

1A, 2A
1B, 2B Bus B

2

Description

Bus Switch Enables

Bus A

TRUTH TABLE

Input OE Function

L

H

 Semiconductor Components Industries, LLC, 2001

August, 2001 – Rev. 0

Connect

Disconnect

ORDERING INFORMATION

Device Package Shipping

74FST3245DW SO–20 38 Units/Rail
74FST3245DWR2 SO–20
74FST3245DT TSSOP–20

74FST3245DTR2 TSSOP–20 2500 Units/Reel
74FST3245QS QSOP–20 55 Units/Rail
74FST3245QSR QSOP–20 2500 Units/Reel

1 Publication Order Number:

1000 Units/Reel

75 Units/Rail

74FST3245/D

74FST3245

MAXIMUM RATINGS

Symbol Parameter Value Unit

V

CC

V

I

V

O

I

IK

I

OK

I

O

I

CC

I

GND

T

STG

T

L

T

J



JA

MSL Moisture Sensitivity Level 1
F

R

V

ESD

I

LATCH–UP

Maximum Ratings are those values beyond which damage to the device may occur. Exposure to these conditions or conditions beyond those
indicated may adversely affect device reliability. Functional operation under absolute maximum–rated conditions is not implied. Functional
operation should be restricted to the Recommended Operating Conditions.

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.

DC Supply Voltage –0.5 to 7.0 V
DC Input Voltage –0.5 to 7.0 V
DC Output Voltage –0.5 to 7.0 V
DC Input Diode Current VI  GND –50 mA
DC Output Diode Current VO  GND –50 mA
DC Output Sink Current 128 mA
DC Supply Current per Supply Pin 100 mA
DC Ground Current per Ground Pin 100 mA
Storage Temperature Range –65 to 150 C
Lead Temperature, 1 mm from Case for 10 Seconds 260 C
Junction Temperature Under Bias 150 C
Thermal Resistance (Note 1) SOIC

TSSOP

QSOP

96
128
200

C/W

Flammability Rating Oxygen Index: 28 to 34 UL 94 V–0 @ 0.125 in
ESD Withstand Voltage Human Body Model (Note 2)

Machine Model (Note 3)

2000

200

V

Latch–Up Performance Above VCC and Below GND at 85C (Note 4) 500 mA

RECOMMENDED OPERATING CONDITIONS

Symbol Parameter Min Max Unit

V

CC

V

I

V

O

T

A

t/V Input Transition Rise or Fall Rate Switch Control Input

5. Unused control inputs may not be left open. All control inputs must be tied to a high or low logic input voltage level.

Supply Voltage Operating, Data Retention Only 4.0 5.5 V
Input Voltage (Note ) 0 5.5 V
Output Voltage (HIGH or LOW State) 0 V

CC

Operating Free–Air Temperature –40 85 C

Switch I/O

0
0

5

DC

V

ns/V

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74FST3245

DC ELECTRICAL CHARACTERISTICS

V

CC

Symbol Parameter Conditions (V) Min Typ* Max Unit

V

IK

V

IH

V

IL

I

I

I

OZ

R

ON

Clamp Diode Resistance IIN = –18mA 4.5 –1.2 V
High–Level Input Voltage 4.0 to 5.5 2.0 V
Low–Level Input Voltage 4.0 to 5.5 0.8 V
Input Leakage Current 0  VIN  5.5 V 5.5 1.0 A
OFF–STATE Leakage Current 0  A, B  V

CC

5.5 1.0 A

Switch On Resistance (Note 6) VIN = 0 V, IIN = 64 mA 4.5 4 7 

VIN = 0 V, IIN = 30 mA 4.5 4 7
VIN = 2.4 V, IIN = 15 mA 4.5 8 15
VIN = 2.4 V, IIN = 15 mA 4.0 11 20

I

CC

I

Quiescent Supply Current VIN = VCC or GND, I
Increase In ICC per Input One input at 3.4 V, Other inputs at VCC or GND 5.5 2.5 mA

CC

= 0 5.5 3 A

OUT

*Typical values are at VCC = 5.0 V and TA = 25C.

6. Measured by the voltage drop between A and B pins at the indicated current through the switch.

AC ELECTRICAL CHARACTERISTICS

VCC = 4.5 to 5.5 V VCC = 4.0 V

Symbol Parameter Conditions Figures Min Max Min Max Unit

t

,

t
t

t
t

t

PHL
PLH

PZH
PZL

PHZ
PLZ

Prop Delay Bus to Bus
(Note 7)

,

Output Enable Time VI = 7 V for t

,

Output Disable Time VI = 7 V for t

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).

VI = OPEN 3 and 4 0.25 0.25 ns

VI = OPEN for t

VI = OPEN for t

PZL

PLZ

PZH

PHZ

3 and 4 1.5 5.9 6.4 ns

3 and 4 1.5 6.0 5.7 ns

TA = –40C to 85C

Limits

TA = –40C to 85C

CAPACITANCE (Note 8)

Symbol Parameter Conditions Typ Max Unit

C

IN

C

I/O

Control Pin Input Capacitance VCC = 5.0 V 3 pF
Input/Output Capacitance VCC, OE = 5.0 V 5 pF

8. TA = 25C, f = 1 MHz, Capacitance is characterized but not tested.

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