Texas Instruments CY74FCT257TQCT, CY74FCT257TQC, CY74FCT257CTSOCT, CY74FCT257CTSOC, CY74FCT257CTQCT Datasheet

Quad 2-Input Multiplexe

r

CY74FCT257T

SCCS019 - May 1994 - Revised February 2000

Data sheet acquired from Cypress Semiconductor Corporation.

Data sheet modified to remove devices not offered.

Copyright © 2000, Texas Instruments Incorporated

Features

• Function, pinout, and drive compatible with FCT and

F logic

• FCT-C speed at 4.3 ns max.

FCT-A speed at 5.0 ns max.

• Reduced V

OH

(typically = 3.3V) versions of equivalent

FCT functions

• Edge-rate control circuitry for significantly improved

noise characteristics

• Power-off disable feature

• Matched rise and fall times

• Fully compatible with TTL input and output logic levels

• ESD > 2000V

• Extended commercial range of −40˚C to +85˚C

• Sink current 64 mA

Source current 32 mA

Functional Description

The FCT257T has four identical two-input multiplexers which

select four bits of data from two sources under the control of a

commondataSelectinput(S).The I

0

inputsareselectedwhen

the Select input is LOW and the I

1

inputs are selected when

the Select input is HIGH. Data appears at the output in true

non-inverted form for the FCT257T.

The FCT257T is a logic implementation of a four-pole, two

position switch where the position of the switch is determined

by the logic levels supplied to the select input. Outputs are

forced to a high-impedance “OFF” state when the Output

Enable input (

OE) is HIGH.

All but one device must be in the high-impedance state to

avoid currents exceeding the maximum ratings if outputs are

tiedtogether.Design of theOutputEnablesignals must ensure

that there is no overlap when outputs of three-state devices

are tied together.

The outputs are designed with a power-off disable feature to

allow for liv e insertion of boards.

Logic Block Diagram Pin Configurations

I

0a

SI

1a

I

0b

I

1b

I

0c

I

1c

I

0d

I

1d

Y

a

Y

b

Y

c

Y

d

OE

1

2

3

4

5

6

7

8

V

CC

GND

Top View

SOIC/QSOP

16

15

14

13

12

11

10

9

Y

a

S

I

1a

I

0a

I

1c

I

0c

OE

Y

b

I

1b

I

0b

I

1d

I

0d

Y

c

Y

d

Y

a

S

I

1a

I

0a

I

1d

I

0d

Y

b

I

1b

I

0b

I

1c

I

0c

Y

c

Y

d

OE

LogicSymbol

Pin Description

Name Description

I Data Inputs

S Common Select Input

OE Enable Inputs (Active LOW)

Y Data Outputs

Function Table

[1]

Inputs Outputs

OE S I

0

I

1

Y

H

L

L

L

L

X

H

H

L

L

X

X

X

L

H

X

L

H

X

X

H

L

H

L

H

Note:

1. H = HIGH Voltage Level, L = LOW Voltage Level, X = Don’t Care,

Z = High impedance (OFF) state.

CY74FCT257T

2

Maximum Ratings

[2,3]

(Above which the useful life may be impaired. For user

guidelines, not tested.)

Storage Temperature .....................................−65°C to +150°C

Ambient Temperature with

Power Applied..................................................−65°C to +135°C

Supply Voltage to Ground Potential..................−0.5V to +7.0V

DC Input Voltage .................................................−0.5V to +7.0V

DC Output Voltage ..............................................−0.5V to +7.0V

DC Output Current (Maximum Sink Current/Pin) ......120 mA

Power Dissipation..........................................................0.5W

Static Discharge Voltage............................................>2001V

(per MIL-STD-883, Method 3015)

Operating Range

Range Range

Ambient

Temperature V

CC

Commercial All −40°C to +85°C 5V ± 5%

Electrical Characteristics Over the Operating Range

Parameter Description Test Conditions Min. Typ.

[4]

Max. Unit

V

OH

Output HIGH Voltage V

CC

=Min., I

OH

=−32 mA 2.0 V

V

OL

Output LOW Voltage V

CC

=Min., I

OL

=64 mA 0.3 0.55 V

V

IH

Input HIGH Voltage 2.0 V

V

IL

Input LOW Voltage 0.8 V

V

H

Hysteresis

[5]

All inputs 0.2 V

V

IK

Input Clamp Diode Voltage V

CC

=Min., I

IN

=−18 mA −0.7 −1.2 V

I

I

Input HIGH Current V

CC

=Max., V

IN

=V

CC

5 µA

I

IH

Input HIGH Current V

CC

=Max., V

IN

=2.7V ±1 µA

I

IL

Input LOW Current V

CC

=Max., V

IN

=0.5V ±1 µA

I

OZH

Off State HIGH-Level Output Current V

CC

= Max., V

OUT

= 2.7V 10 µA

I

OZL

Off State LOW-Level

Output Current

V

CC

= Max., V

OUT

= 0.5V −10 µA

I

OS

Output Short Circuit Current

[6]

V

CC

=Max., V

OUT

=0.0V −60 −120 −225 mA

I

OFF

Power-Off Disable V

CC

=0V, V

OUT

=4.5V ±1 µA

Capacitance

[5]

Parameter Description Typ.

[4]

Max. Unit

C

IN

Input Capacitance 5 10 pF

C

OUT

Output Capacitance 9 12 pF

Notes:

2. Unless otherwise noted, these limits are over the operating free-air temperature range.

3. Unused inputs must always be connected to an appropriate logic voltage level, preferably either V

CC

or ground.

4. Typical values are at V

CC

=5.0V, T

A

=+25˚C ambient.

5. This parameter is specified but not tested.

6. Not morethanone output should beshorted ata time. Duration ofshort should notexceed one second. Theuse of high-speed test apparatusand/or sample

and holdtechniques are preferableinorder to minimize internalchipheating and more accuratelyreflect operational values.Otherwise prolonged shorting of

a high output mayraise the chip temperature well above normal and therebycauseinvalid readings in other parametric tests. In anysequence of parameter

tests, I

OS

tests should be performed last.